(Address, including zip code, and telephone number, including area code, of registrants principal executive offices)

David J. Mazzo, Ph.D.

President and Chief Executive Officer

Regado Biosciences, Inc.

120 Mountain View Boulevard

Basking Ridge, New Jersey 07920

(908) 580-2100

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Michael J. Lerner

John D. Hogoboom

Lowenstein Sandler LLP

1251 Avenue of the Americas

New York, New York 10020 (212) 262-6700

Michael D. Maline

Edward A. King

Goodwin Procter LLP

The New York Times Building

620 Eighth Avenue

New York, New York 10018

(212) 813-8800

Approximate date of commencement of proposed sale to the public: As soon as practicable after the
effective date of this Registration Statement.

If any of the securities being registered on this Form are to be offered on a
delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box. ¨

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please
check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list
the Securities Act registration statement number of the earlier effective registration statement for the same offering. ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list
the Securities Act registration statement number of the earlier effective registration statement for the same offering. ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller
reporting company. See the definitions of large accelerated filer, accelerated filer and smaller reporting company in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer ¨

Accelerated filer ¨

Non-accelerated filer x (Do not check if a
smaller reporting company)

Smaller reporting company ¨

The registrant is an emerging growth company as defined in Section 2(a) of the Securities
Act. This registration statement complies with the requirements that apply to an issuer that is an emerging growth company.

The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which
specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the Registration Statement shall become effective on such date as the Commission,
acting pursuant to said Section 8(a), may determine.

The information in this preliminary prospectus is not complete and may be changed. These
securities may not be sold until the registration statement filed with the Securities and Exchange Commission is effective. This preliminary prospectus is not an offer to sell nor does it seek an offer to buy these securities in any state or other
jurisdiction where the offer or sale is not permitted.

PROSPECTUS (Subject to Completion)

Dated May 29, 2013

5,000,000 Shares

Common Stock

This is the initial public offering of shares of our common stock. We are offering 5,000,000 shares of our common stock. Prior to this offering, there has been no public market for our common stock. We
have applied to list our common stock on The NASDAQ Global Market under the symbol RGDO. We expect that the public offering price will be between $14.00 and $16.00 per share.

We are an emerging growth company as that term is used in the Jumpstart Our Business Startups Act of 2012 and, as such, have elected to comply with certain reduced public company reporting
requirements for this prospectus and future filings. See Prospectus Summary  Implications of Being an Emerging Growth Company.

Our business and an investment in our common stock involve significant risks. These risks are described under the caption Risk Factors beginning on page 10 of
this prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these
securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

Per Share

Total

Public offering price

$

$

Underwriting discount(1)

$

$

Proceeds, before expenses, to us

$

$

(1)

We refer you to Underwriting beginning on page 134 of this prospectus for additional information regarding total underwriter compensation.

The underwriters may also purchase up to an additional 750,000 shares from us at the public offering price, less the
underwriting discount, within 30 days from the date of this prospectus to cover overallotments, if any.

Certain of our existing stockholders,
including stockholders affiliated with certain of our directors, have indicated an interest in purchasing up to an aggregate of approximately $29.5 million in shares of our common stock in this offering at the initial public offering price.
However, because indications of interest are not binding agreements or commitments to purchase, the underwriters could determine to sell more, less or no shares to any of these potential investors and any of these potential investors could determine
to purchase more, less or no shares in this offering.

The underwriters expect to deliver the shares against payment in New York, New York on
, 2013.

For investors outside the United States: neither we nor the underwriters have done
anything that would permit this offering or possession or distribution of this prospectus or any free writing prospectus we may provide to you in connection with this offering in any jurisdiction where action for that purpose is required, other than
in the United States. You are required to inform yourselves about and to observe any restrictions relating to this offering and the distribution of this prospectus and any such free writing prospectus outside of the United States.

You should rely only on the information contained in this prospectus and any related free writing prospectus that we may provide to
you in connection with this offering. We have not, and the underwriters have not, authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. We
are not, and the underwriters are not, making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information appearing in this prospectus is accurate only as of the date on the
front cover of this prospectus. Our business, financial condition, results of operations and prospects may have changed since that date.

This summary provides an overview of selected information contained elsewhere in this prospectus and does not contain all of the
information you should consider before investing in our common stock. You should carefully read this prospectus and the registration statement of which this prospectus is a part in their entirety before investing in our common stock, including the
information discussed under Risk Factors beginning on page 10 and our financial statements and notes thereto that appear elsewhere in this prospectus. As used in this prospectus, the terms we, our, us,
or the Company refer to Regado Biosciences, Inc.

Our Company

We are a biopharmaceutical company focused on the discovery and development of novel, first-in-class, actively controllable antithrombotic
drug systems for acute and sub-acute cardiovascular indications. We are pioneering the discovery and development of two-component drug systems consisting of a therapeutic aptamer and its specific active control agent. Our actively controllable
product candidates have the potential to improve outcomes, enhance the patient experience and reduce overall treatment costs.

Our Lead
Product Candidate

REG1 is an actively controllable anticoagulant targeting coagulation Factor IXa for use in patients with
a wide variety of acute coronary syndromes, or ACS, undergoing a percutaneous coronary intervention, or PCI, a hospital-based procedure used to mechanically open or widen obstructed coronary arteries. REG1 consists of pegnivacogin, an anticoagulant
aptamer, and its specific active control agent, anivamersen. Pegnivacogin achieves its maximal anticoagulant effect within five minutes of injection. Anivamersen is an oligonucleotide, a biological polymer consisting of a relatively small number of
nucleotides chemically bound in a linear sequence that forms a chain-like structure, or strand, and has no pharmacologic activity other than to bind to pegnivacogin. Anivamersen rapidly and precisely reduces or eliminates the anticoagulant activity
of pegnivacogin. Both pegnivacogin and anivamersen are administered by intravenous bolus injection using weight-based dosing. By adjusting the dose of anivamersen relative to pegnivacogin, the anticoagulant effect of pegnivacogin can be precisely
and rapidly controlled or eliminated. The unprecedented level of control that REG1 provides permits physicians to achieve levels of anticoagulation in patients that would be unsafe to use with existing anticoagulants.

PCI procedures involve a significant risk of ischemic events, including death, stroke, myocardial infarction and the need for
revascularization of the artery. Because of this risk, powerful anticoagulant drugs are administered prior to and throughout the PCI procedure. However, anticoagulants create a significant risk of major bleeding events. As a result, interventional
cardiologists are forced to make a compromising medical decision because they lack the means to simultaneously reduce the risks of ischemic and major bleeding events.

REG1 is the first and only anticoagulant to demonstrate a reduction in both ischemic and major bleeding events in a clinical trial for PCI. In our randomized, partially blinded, dose-ranging Phase 2b
trial involving 640 subjects, or the RADAR trial, when compared to standard of care heparin, REG1 demonstrated both a rapid and predictable anticoagulant effect and the ability to precisely modulate or eliminate that effect in real time. REG1 also
demonstrated the following important clinical and pharmacoeconomic benefits:



an approximate 66.0% reduction in ischemic events;



a reduction of up to 60.0% in major bleeding events;



a substantial reduction in time from catheterization to catheter sheath removal from a median of 3.8 hours to a median of one hour;



a substantial reduction in time from completion of the PCI procedure to catheter sheath removal from a median of three hours to a median of 24 minutes;
and



a substantial reduction in the time subjects were required to remain still following catheter sheath removal from a median of 5.7 hours to a median of
2.8 hours.

Based on these clinical results and after discussion with the U.S. Food and Drug
Administration, or FDA, and the European Medicines Agency, we intend to initiate a single, open-label, 13,200 subject Phase 3 trial of REG1, or the REGULATE-PCI trial, in the second half of 2013. REGULATE-PCI, if successful, will serve as the basis
for product registration applications worldwide.

We believe that REG1 has the potential to become the standard of care for
anticoagulation therapy in PCI and other cardiovascular procedures because it gives physicians precise, on-demand control over anticoagulation levels. We believe the key advantages of REG1 over existing therapies are the following:



Reduced ischemic events. REG1 allows a higher level of anticoagulation to be used safely during PCI, which will reduce the
occurrence of ischemic events.



Reduced major bleeding events. REG1s anticoagulant effect can be modulated or eliminated at the end of PCI
which will reduce the risk of major bleeding events.



Precise and predictable dosing.Because REG1s effect is independent of an individual patients
metabolism or health, dosing is precise and predictable, thereby eliminating the need for time-consuming and costly patient monitoring during and after PCI.



Broad applicability.REG1s use in PCI is unrestricted for high risk patients such as those with kidney or
liver impairment.

We believe that REG1 has potential for use in other PCI and interventional cardiovascular procedures, such as open heart surgery, PCI as a
treatment for ST segment elevation myocardial infarction as well as transcatheter aortic valve replacement or implantation.

PCI Overview

PCIs are hospital-based procedures used to mechanically open or widen obstructed coronary arteries. According to the
American Heart Association, approximately 950,000 PCIs were performed in the United States in 2010. We estimate that in 2010 approximately 1.1 million PCIs were performed in Europe and at least 1.0 million PCIs were performed in the rest
of the world. Based upon the estimated cost per procedure of branded anticoagulants, we believe that this represents a greater than $3.0 billion annual market opportunity for anticoagulants used in PCI procedures. We believe that an antithrombotic
treatment that can address the shortcomings of existing anticoagulants would establish a new standard of care.

Our Proprietary Technology
Platform

Our aptamers are single strands of nucleic acids, or oligonucleotides, that are chemically synthesized. Unlike
other oligonucleotides, which are designed to control gene expression, an aptamer has a unique geometric shape that binds specifically and tightly to a target protein molecule, leading to inhibition of the targets activity. Aptamers have been
discovered that interact with essentially every class of therapeutic protein target. An aptamers pharmacologic activity can be controlled by interaction with a complementary oligonucleotide, which we term a specific active control agent. When
the specific active control agent binds to the aptamer, it changes the aptamers shape thereby eliminating its therapeutic activity. We believe that the following factors give us a competitive advantage:



a proven discovery team including the co-inventor of active aptamer control agent technology;

an exclusive license to the patents covering active aptamer control agent technology, which include broad claims for methods to design and administer
agents to control aptamer activity in the body;



a commercial license to a combinatorial chemistry technology platform for aptamer discovery and development;



the know-how to identify, isolate and optimize therapeutic aptamers and their active control agents, which has led to the discovery of multiple product
candidates;



a proven pharmaceutical development team with experience in the development of efficient and economical manufacturing processes for aptamers and active
control agents; and



an extensive clinical database of systemic aptamer use, which gives us unparalleled expertise in the discovery of new two-component aptamer-based
product candidates.

Aptamer technology has evolved significantly since first generation aptamers were
described in 1990. Our product candidates consist of third and fourth generation aptamers which have significantly improved pharmaceutic and pharmacokinetic stability and have not shown immunological activity present in earlier generation aptamers.

Additional Pipeline Opportunities

Using our proprietary technology platform, we are developing a portfolio of additional clinical candidates in acute and sub-acute cardiovascular and other indications. REG3 is a preclinical stage
antiplatelet therapy, consisting of a glycoprotein VI, or GPVI, inhibitor being evaluated in diabetic vasculopathy and other inflammatory diseases. The specific active control agent component of REG3 is designed to permit modulation or reversal of
the GPVI inhibition, if necessary, to optimize dosing and minimize unwanted side effects that might result from GPVI inhibition. We plan to initiate a Phase 1 study of REG3 in 2014. REG2 is an early clinical stage program evaluating an extended
release formulation of pegnivacogin intended to provide a controllable level of anticoagulation for up to two weeks for venous antithrombotic applications such as venous thromboembolism, or VTE, prophylaxis. In REG2, anivamersen would be used as an
active control agent, if needed. We have completed a single escalating dose Phase 1 clinical trial of REG2 and plan to conduct additional clinical testing in the future. Additionally, we are evaluating potential product candidates against the
receptor CLEC-2, an antiplatelet target.

The following table lists our current product candidates and discovery programs and
their respective stages of development:

Our product candidates and proprietary technology platform are protected by a patent
estate of 30 issued or allowed patents, including 14 in the United States, covering the composition of matter and methods of use for our product candidates as well as our fundamental controllable aptamer technology. We maintain worldwide
commercialization rights to all of our product candidates except in Armenia, Azerbaijan, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Moldova, Russia, Tajikistan, Turkmenistan, Ukraine and Uzbekistan.

Our Risks

An investment
in our common stock involves a high degree of risk. You should carefully consider the risks summarized below. These risks are discussed more fully in the Risk Factors section of this prospectus immediately following this prospectus
summary. These risks include, but are not limited to, the following:



we have a limited operating history and have incurred operating losses of approximately $115.2 million from inception through March 31, 2013;



we will need to obtain additional financing to complete REGULATE-PCI;



clinical trials for our product candidates, including REGULATE-PCI, may not be successful;



we are heavily dependent on the success of our lead product candidate, REG1;



we have not completed clinical development of any of our product candidates and do not have any products approved for sale by the FDA or any other
regulatory bodies;



we rely on third parties to manufacture our product candidates and to conduct our clinical trials;



we currently do not have the infrastructure to commercialize any of our product candidates if such products receive regulatory approval; and



we depend on our ability to attract and retain scientists, clinicians and sales personnel with extensive experience in drug development and
commercialization.

Implications of Being an Emerging Growth Company

We are an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012, or the JOBS Act, and, for as
long as we continue to be an emerging growth company, we may choose to take advantage of exemptions from various reporting requirements applicable to other public companies but not to emerging growth companies, including, but
not limited to, not being required to comply with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act of 2002, reduced disclosure obligations regarding executive compensation in our periodic reports and proxy
statements, and exemptions from the requirements of holding a nonbinding advisory vote on executive compensation and stockholder approval of any golden parachute payments not previously approved. We could be an emerging growth company
for up to five years, or until the earliest of (i) the last day of the first fiscal year in which our annual gross revenues exceed $1 billion, (ii) the date that we become a large accelerated filer as defined in Rule 12b-2
under the Securities Exchange Act of 1934, as amended, which would occur if the market value of our common stock that is held by non-affiliates exceeds $700 million as of the last business day of our most recently completed second fiscal quarter, or
(iii) the date on which we have issued more than $1 billion in non-convertible debt during the preceding three-year period. We are choosing to opt out of the extended transition periods available under the JOBS Act for complying
with new or revised accounting standards, and intend to take advantage of the other exemptions.

We were incorporated in Delaware under the name Quartet Biosciences, Inc. in December 2001 and changed our name to Regado Biosciences, Inc. in March 2003. Our principal executive offices are located at
120 Mountain View Boulevard, Basking Ridge, New Jersey 07920, and our telephone number is (908) 580-2100. Our website address is www.regadobio.com. Our website and the information contained on, or that can be accessed through, our website will
not be deemed to be incorporated by reference in, and are not considered part of, this prospectus. You should not rely on our website or any such information in making your decision whether to purchase our common stock.

We estimate that we will receive net proceeds of approximately $68.3 million from the sale of the shares of common stock offered in this offering, or approximately $78.7 million if the
underwriters exercise their overallotment option in full, based on an assumed initial public offering price of $15.00 per share (the midpoint of the price range set forth on the cover page of this prospectus) and after deducting the estimated
underwriting discount and estimated offering expenses payable by us. We intend to use the net proceeds from this offering to fund further clinical development of REG1 and for working capital and other general corporate purposes. See the section
entitled Use of Proceeds for a more complete description of the intended use of proceeds from this offering.

Risk factors

See the section entitled Risk Factors and other information included in this prospectus for a discussion of factors you should carefully consider before deciding to invest in shares
of our common stock.

Proposed NASDAQ Global Market symbol

RGDO

Certain of our existing stockholders, including
stockholders affiliated with certain of our directors, have indicated an interest in purchasing up to an aggregate of approximately $29.5 million in shares of our common stock in this offering at the initial public offering price. However,
because indications of interest are not binding agreements or commitments to purchase, the underwriters could determine to sell more, less or no shares to any of these potential investors and any of these potential investors could determine to
purchase more, less or no shares in this offering. Any shares purchased by our existing stockholders will be subject to lock-up restrictions described in Shares Eligible for Future Sale.

The number of shares of our common stock to be outstanding after this offering is 14,618,039, based on 9,618,039 shares of our common
stock outstanding as of March 31, 2013 (including convertible preferred stock on an as-converted basis), and excludes the following:



1,441,252 shares of our common stock issuable upon the exercise of stock options outstanding at a weighted-average exercise price of $7.18 per share;



901,023 shares of our common stock (assuming the sale of 5,000,000 shares of our common stock in this offering) issuable upon the exercise of options
granted under our 2013 Equity Compensation Plan, or the 2013 Plan, which will become effective upon the consummation of this offering and will have an exercise price equal to the initial public offering price set forth on the cover page of this
prospectus;



up to 781,089 shares of our common stock reserved for future awards under the 2013 Plan (assuming the sale of 5,000,000 shares of our common stock in
this offering);

The following tables summarize our financial data. We derived the following summary of our statement of operations data for the years
ended December 31, 2012, and 2011 from our audited financial statements and related notes included elsewhere in this prospectus. We derived the following summary of our statement of operations data for the three months ended March 31, 2013
and 2012 and the balance sheet data as of March 31, 2013 from our unaudited financial statements and related notes included elsewhere in this prospectus. Our interim unaudited financial statements have been prepared in accordance with generally
accepted accounting principles in the United States of America on the same basis as the annual audited financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments, necessary to a
fair statement of our financial position as of March 31, 2013 and our results of our operations for the three months ended March 31, 2013 and 2012. The results for the three months ended March 31, 2013 are not necessarily indicative
of results to be expected for the year ending December 31, 2013, any other interim periods or any future period or year. You should read this information together with the sections entitled Capitalization, Selected Financial
Data, Managements Discussion and Analysis of Financial Condition and Results of Operations and our financial statements and related notes included elsewhere in this prospectus.

See Note 8 of our Notes to Financial Statements appearing elsewhere in this prospectus for an explanation of the method used to calculate the basic and diluted net loss
per common share.

(2)

The calculations for the unaudited pro forma net loss per common share, basic and diluted, assume the conversion of all our outstanding shares of convertible preferred
stock into shares of our common stock, as if the conversion had occurred at the beginning of the period presented.

Pro forma balance sheet data have been calculated assuming the conversion of our outstanding shares of preferred stock into an aggregate of 9,396,776 shares of our
common stock.

(2)

The pro forma as adjusted column reflects the pro forma adjustments described in footnote (1) above and the sale by us of 5,000,000 shares of common stock in this
offering at an assumed initial public offering price of $15.00 per share, the midpoint of the price range set forth on the cover page of this prospectus, after deducting the estimated underwriting discount and estimated offering expenses payable by
us.

(3)

A $1.00 increase (decrease) in the assumed initial public offering price of $15.00 per share would increase (decrease) each of cash, cash equivalents and short-term
investments, working capital and total assets by approximately $4.7 million and increase (decrease) additional paid-in capital by approximately $4.7 million, assuming the number of shares we are offering, as set forth on the cover page of this
prospectus, remains the same, after deducting the estimated underwriting discount and estimated offering expenses payable by us. We may also increase or decrease the number of shares we are offering. An increase (decrease) of 1,000,000 shares in the
number of shares we are offering would increase (decrease) each of cash, cash equivalents and short-term investments, working capital and total assets by approximately $14.0 million, increase (decrease) common stock by $1,000 and increase (decrease)
additional paid-in capital by approximately $14.0 million, assuming an initial public offering price per share of $15.00, which is the midpoint of the price range set forth on the cover page of this prospectus. The pro forma as adjusted information
is illustrative only, and we will adjust this information based on the actual initial public offering price, number of shares offered and other terms of this offering determined at pricing.

An investment in shares of our common stock involves a high degree of risk. You should carefully consider the following information
about these risks, together with the other information appearing elsewhere in this prospectus, before deciding to invest in our common stock. The occurrence of any of the following risks could have a material adverse effect on our business,
financial condition, results of operations and future growth prospects. In these circumstances, the market price of our common stock could decline, and you may lose all or part of your investment.

Risks Relating to Our Financial Position and Need for Additional Capital

We have never been profitable. Currently, we have no products approved for commercial sale, and to date we have not generated any revenue from product sales. As a result, our ability to curtail our
losses and reach profitability is unproven, and we may never achieve or sustain profitability.

We have never been
profitable and do not expect to be profitable in the foreseeable future. We have incurred net losses in each year since our inception, including net losses of approximately $13.1 million and $19.2 million for 2012 and 2011, respectively. For the
three months ended March 31, 2013, we incurred a net loss of $3.3 million, and as of March 31, 2013, we had an accumulated deficit of approximately $113.8 million. We have devoted most of our financial resources to research and
development, including our preclinical development activities and clinical trials. We have not completed development of any product candidate and we have therefore not generated any revenues from product sales. Because of the numerous risks and
uncertainties associated with pharmaceutical product development, we are unable to accurately predict the timing or amount of increased expenses or when, or if, we will be able to achieve or maintain profitability. We expect to incur increased
expenses as we commence our single, open-label 13,200 subject Phase 3 trial of REG1, or the REGULATE-PCI trial, in the second half of 2013, advance our other product candidates and expand our research and development programs. We also expect an
increase in our expenses associated with creating additional infrastructure to support operations as a public company. As a result, we expect to continue to incur net losses and negative cash flows for the foreseeable future. These net losses and
negative cash flows have had, and will continue to have, an adverse effect on our stockholders equity and working capital.

To date, we have financed our operations through the sale of our equity and debt securities, bank borrowings and government grants. The
amount of our future net losses will depend, in part, on the rate of future growth of our expenses and our ability to generate revenues. In addition, we may not be able to enter into any collaborations that will generate significant cash. If we are
unable to develop and commercialize one or more of our product candidates either alone or with collaborators, or if revenues from any product candidate that receives marketing approval are insufficient, we will not achieve profitability. Even if we
do achieve profitability, we may not be able to sustain or increase profitability.

We will need additional capital to
complete the REGULATE-PCI trial and commercialize REG1. If we are unable to raise sufficient capital, we would be forced to delay, reduce or eliminate our product development programs.

Developing pharmaceutical products, including conducting preclinical studies and clinical trials, is expensive. We expect our research and
development expenses to increase in connection with our ongoing activities, particularly as we commence our REGULATE-PCI trial, undertake additional clinical trials of our other product candidates and continue to work on our other research programs.
We believe that the net proceeds of this offering will be sufficient for us to fund the REGULATE-PCI trial through the interim analysis at 50% enrollment, which we expect will occur by the end of 2014. Because the expected net proceeds of this
offering will not be sufficient for us to complete the REGULATE-PCI trial, we will need to raise substantial additional capital to complete the development and commercialization of REG1. If the U.S. Food and Drug Administration, or the FDA, or other
regulators require that we perform additional studies beyond those we currently expect, or if there are any delays in completing our clinical trials or the development of any of our product candidates, our expenses could increase beyond what we
currently anticipate and the timing of any potential product approval may be delayed. Except for potential additional sales of our Series E Preferred Stock as described in Certain

Relationships and Related Party TransactionsSeries E Financing, we have no commitments or arrangements for any additional financing to fund our research and development programs.
We also will need to raise substantial additional capital in the future to complete the development and commercialization of REG1 for additional indications and for our other product candidates. Because successful development of our product
candidates is uncertain, we are unable to estimate the actual funds required to complete research and development and commercialize our products under development.

Until we can generate a sufficient amount of revenue from our product candidates, if ever, we expect to finance future cash needs through public or private equity offerings, debt financings or corporate
collaborations and licensing arrangements. Additional funds may not be available when we need them on terms that are acceptable to us, or at all. If adequate funds are not available, we may be required to delay, reduce the scope of or eliminate one
or more of our research or development programs. To the extent that we raise additional funds by issuing equity securities, our stockholders will experience additional dilution, and debt financing, if available, may involve restrictive covenants. To
the extent that we raise additional funds through collaborations and licensing arrangements, it may be necessary to relinquish some rights to our technologies or our product candidates or grant licenses on terms that may not be favorable to us. We
may seek to access the public or private capital markets whenever conditions are favorable, even if we do not have an immediate need for additional capital at that time.

Our future funding requirements, both near and long-term, will depend on many factors, including, but not limited to:



the initiation, progress, timing, costs and results of preclinical studies and clinical trials for our product candidates and potential product
candidates, including our REGULATEPCI trial and the continued development of our other product candidates;



the number and characteristics of product candidates that we pursue;



the terms and timing of any future collaboration, licensing or other arrangements that we may establish;

the cost and timing of completing commercial-scale outsourced manufacturing activities;



market acceptance of any product candidates for which we may receive regulatory approval;



the cost of establishing sales, marketing and distribution capabilities for any product candidates for which we may receive regulatory approval; and



the extent to which we acquire, license or invest in businesses, products or technologies.

We have a limited operating history and we expect a number of factors to cause our operating results to fluctuate on a quarterly
and annual basis, which may make it difficult to predict our future performance.

We are a development stage
biopharmaceutical company with a limited operating history. Our operations to date have been primarily limited to developing our technology and undertaking preclinical studies and clinical trials of REG1 and any of our other product candidates. We
have not yet obtained regulatory approvals for REG1 or any of our other product candidates. Consequently, any predictions made about our future success or viability may not be as accurate as they could be if we had a longer operating history or
commercialized products. Our financial condition and operating results have varied significantly in the past and will continue to fluctuate from quarter-to-quarter or year-to-year due to a variety of factors, many of which are beyond our control.
Factors relating to our business that may contribute to these fluctuations include other factors described elsewhere in this prospectus and also include:

the success of our clinical trials through all phases of clinical development, including our REGULATE-PCI trial;



any delays in regulatory review and approval of product candidates in clinical development;



our ability to obtain and maintain regulatory approval for REG1 or any of our other product candidates in the United States and foreign jurisdictions;



potential side effects of our product candidates that could delay or prevent commercialization, limit the indications for any approved drug, require
the establishment of risk evaluation and mitigation strategies, or REMS, or cause an approved drug to be taken off the market;



our dependence on third-party manufacturers, or CMOs, to supply or manufacture our products;



our dependence on clinical research organizations, or CROs, to conduct our clinical trials;



our ability to establish or maintain collaborations, licensing or other arrangements;



market acceptance of our product candidates;



our ability to establish and maintain an effective sales and marketing infrastructure, either through the creation of a commercial infrastructure or
through strategic collaborations;



competition from existing products or new products that may emerge;



the ability of patients or healthcare providers to obtain coverage of or sufficient reimbursement for our products;

Based on our cash balances, recurring losses, net capital deficiency and debt outstanding as of December 31, 2012 and our projected
spending in 2013, which raise substantial doubt about our ability to continue as a going concern, the audit opinion on our audited financial statements as of and for the year ended December 31, 2012 contains a going concern modification. We
believe that the net proceeds from this offering, the proceeds from our sale of additional shares of Series E Preferred Stock and existing cash and cash equivalents and interest thereon, will be sufficient to fund our projected operating
requirements through the end of 2014. However, if we are unable to continue as a going concern, we might have to liquidate our assets and the values we receive for our assets in liquidation or dissolution could be significantly lower than the values
reflected in our financial statements. Amounts due under our loan with Comerica Bank, or Comerica, may become immediately due and payable upon the occurrence of a material adverse change, as defined under the loan agreement. Under the terms of the
Comerica loan agreement, we are subject to operational covenants, including limitations on our ability to

incur liens or additional debt, pay dividends, redeem stock, make specified investments and engage in merger, consolidation or asset sale transactions, among other restrictions. In addition, the
inclusion of a going concern statement by our auditors, our lack of cash resources and our potential inability to continue as a going concern may materially adversely affect our share price and our ability to raise new capital or to enter into
critical contractual relations with third parties.

Risks Relating to the Development and Regulatory Approval of Our Product Candidates

Clinical failure can occur at any stage of clinical development. Because the results of earlier clinical trials are
not necessarily predictive of future results, any product candidate we advance through clinical trials may not have favorable results in later clinical trials or receive regulatory approval.

Clinical failure can occur at any stage of clinical development. Clinical trials may produce negative or inconclusive results, and we may
decide, or regulators may require us, to conduct additional clinical or preclinical trials. In addition, data obtained from trials are susceptible to varying interpretations, and regulators may not interpret our data as favorably as we do, which may
delay, limit or prevent regulatory approval. Success in preclinical testing and early clinical trials does not ensure that later clinical trials will generate the same results or otherwise provide adequate data to demonstrate the efficacy and safety
of a product candidate. Frequently, product candidates that have shown promising results in early clinical trials have subsequently suffered significant setbacks in later clinical trials. In addition, the design of a clinical trial can determine
whether its results will support approval of a product and flaws in the design of a clinical trial may not become apparent until the clinical trial is well advanced. While members of our management team have experience in designing clinical trials,
our company has limited experience in designing clinical trials and we may be unable to design and execute a clinical trial to support regulatory approval. Further, clinical trials of potential products often reveal that it is not practical or
feasible to continue development efforts. For example, if the results of our REGULATE-PCI trial do not achieve the primary efficacy endpoints or demonstrate expected safety, the prospects for approval of REG1 would be materially and adversely
affected. If REG1 or our other product candidates are found to be unsafe or lack efficacy, we will not be able to obtain regulatory approval for them and our business would be harmed.

REGULATE-PCI includes three interim analyses of REG1 by the Data Safety Monitoring Board, or the DSMB. The first interim analysis will be
a general safety analysis after enrollment of 1,000 subjects, which is expected to occur by the end of the second quarter of 2014. The second interim analysis will be another general safety analysis after 25% of the subjects are enrolled, which is
expected to occur by the end of the third quarter of 2014. The final interim analysis will be an analysis of the general safety and efficacy of REG1 after 50% of the subjects are enrolled, which is expected to occur by the end of 2014. If, as a
result of any of those interim analyses, we or the DSMB determine that REG1 is not safe or that it is futile to continue the trial because of a lack of efficacy, the trial will be terminated. If the results of any one of these analyses is
unfavorable, our business would be harmed.

We cannot be certain that REG1 or any of our other product candidates will
receive regulatory approval, and without regulatory approval we will not be able to market our product candidates. Any delay in the regulatory review or approval of REG1 or any of our other product candidates will materially or adversely harm our
business.

We have invested a significant portion of our efforts and financial resources in the development of REG1,
our most advanced product candidate. Our ability to generate revenue related to product sales, which we do not expect will occur for at least the next several years, if ever, will depend on the successful development and regulatory approval of our
product candidates. We plan to commence our REGULATE-PCI trial in the second half of 2013. We may conduct our REGULATE-PCI trial only to learn that REG1 is not a safe or effective treatment, in which case the REGULATE-PCI trial may not lead to
regulatory approval for REG1. Similarly, our clinical development programs for our other product candidates may not lead to regulatory approval from the FDA and similar foreign regulatory agencies. This failure to obtain regulatory approvals would
prevent our product candidates from being marketed and would have a material and adverse effect on our business.

All of our product candidates require regulatory review and approval prior to
commercialization. Any delays in the regulatory review or approval of our product candidates would delay market launch, increase our cash requirements and result in additional operating losses.

The process of obtaining FDA and other required regulatory approvals, including foreign approvals, often takes many years and can vary
substantially based upon the type, complexity and novelty of the products involved. Furthermore, this approval process is extremely complex, expensive and uncertain. We may be unable to submit any new drug application, or an NDA, in the United
States or any marketing approval application in foreign jurisdictions for any of our products. If we submit an NDA including any amended NDA or supplemental NDA, to the FDA seeking marketing approval for any of our product candidates, the FDA must
decide whether to accept or reject the submission for filing. We cannot be certain that any of these submissions will be accepted for filing and reviewed by the FDA, or that the marketing approval application submissions to any other regulatory
authorities will be accepted for filing and review by those authorities. We cannot be certain that we will be able to respond to any regulatory requests during the review period in a timely manner, or at all, without delaying potential regulatory
action. We also cannot be certain that any of our product candidates will receive favorable recommendations from any FDA advisory committee or foreign regulatory bodies or be approved for marketing by the FDA or foreign regulatory authorities. In
addition, delays in approvals or rejections of marketing applications may be based upon many factors, including regulatory requests for additional analyses, reports, data and studies, regulatory questions regarding data and results, changes in
regulatory policy during the period of product development and the emergence of new information regarding REG1 or our other product candidates.

Data obtained from preclinical studies and clinical trials are subject to different interpretations, which could delay, limit or prevent regulatory review or approval of any of our product candidates.
Furthermore, regulatory attitudes towards the data and results required to demonstrate safety and efficacy can change over time and can be affected by many factors, such as the emergence of new information, including on other products, policy
changes and agency funding, staffing and leadership. We do not know whether future changes to the regulatory environment will be favorable or unfavorable to our business prospects.

In addition, the environment in which our regulatory submissions may be reviewed changes over time. For example, average review times at
the FDA for NDAs have fluctuated over the last ten years, and we cannot predict the review time for any of our submissions with any regulatory authorities. Review times can be affected by a variety of factors, including budget and funding levels and
statutory, regulatory and policy changes. Moreover, in light of widely publicized events concerning the safety risk of certain drug products, regulatory authorities, members of the U.S. Government Accountability Office, medical professionals and the
general public have raised concerns about potential drug safety issues. These events have resulted in the withdrawal of drug products, revisions to drug labeling that further limit use of the drug products and establishment of REMS measures that
may, for instance, restrict distribution of drug products. The increased attention to drug safety issues may result in a more cautious approach by the FDA to clinical trials. Data from clinical trials may receive greater scrutiny with respect to
safety, which may make the FDA or other regulatory authorities more likely to terminate clinical trials before completion, or require longer or additional clinical trials that may result in substantial additional expense and a delay or failure in
obtaining approval or may result in approval for a more limited indication than originally sought.

Delays in the
commencement, enrollment and completion of our clinical trials could result in increased costs to us and delay or limit our ability to obtain regulatory approval for REG1 and our other product candidates.

Delays in the commencement, enrollment and completion of clinical trials could increase our product development costs or limit the
regulatory approval of our product candidates. We plan to commence our REGULATE-PCI trial in the second half of 2013; however, this clinical trial may not be initiated or completed on schedule, if at all. In addition, we do not know whether planned
clinical trials of REG1 in additional indications and of our other product candidates will begin on time or will be completed on schedule or at all. The

commencement, enrollment and completion of our REGULATE-PCI trial or other clinical trials can be delayed for a variety of reasons, including:



inability to reach agreements on acceptable terms with prospective CROs and trial sites, the terms of which can be subject to extensive negotiation and
may vary significantly among different CROs and trial sites;



regulatory objections to commencing a clinical trial;



inability to identify and maintain a sufficient number of trial sites, many of which may already be engaged in other clinical trial programs, including
some that may be for the same indication as our product candidates;



withdrawal of clinical trial sites from our clinical trials as a result of changing standards of care or the ineligibility of a site to participate in
our clinical trials;

difficulty recruiting and enrolling subjects to participate in clinical trials for a variety of reasons, including meeting the enrollment criteria for
our study and competition from other clinical trial programs for the same indication as our product candidates;



inability to retain subjects in clinical trials due to the treatment protocol, personal issues, side effects from the therapy or lack of efficacy; and

lack of adequate funding to continue the clinical trial due to unforeseen costs resulting from enrollment delays, requirements to conduct additional
trials and studies, increased expenses associated with the services of our CROs and other third parties or other reasons.

If we are required to conduct additional clinical trials or other testing of REG1 or our other product candidates beyond those currently contemplated, we may be delayed in obtaining, or may not be able to
obtain, marketing approval for these product candidates.

We have never conducted a Phase 3 clinical trial or
submitted an NDA before, and may be unable to do so for REG1 and other product candidates we are developing.

We intend
to commence our REGULATE-PCI trial in the second half of 2013. The conduct of Phase 3 clinical trials and the submission of a successful NDA is a complicated process. Although members of our management team have extensive industry experience,
including in the development, clinical testing and commercialization of drug candidates, our company has never conducted a Phase 3 clinical trial before, has limited experience in preparing, submitting and prosecuting regulatory filings, and
has not submitted an NDA before. Consequently, we may be unable to successfully and efficiently execute and complete these planned clinical trials in a way that leads to NDA submission and approval of REG1 and other product candidates we are
developing. We may require more time and incur greater costs than our competitors and may not succeed in

obtaining regulatory approvals of product candidates that we develop. Failure to commence or complete, or delays in, our planned clinical trials would prevent or delay commercialization of REG1
and other product candidates we are developing.

We have never performed a clinical trial comparing the safety or
efficacy of REG1 to bivalirudin. Because our clinical trials used heparin as a comparator, the risk that our REGULATE-PCI trial does not achieve one or more of its primary endpoints may be increased.

We have never performed a clinical trial directly comparing the safety or efficacy of REG1 to bivalirudin. Our randomized, partially
blinded, dose-ranging Phase 2b trial involving 640 subjects, or the RADAR trial, used standard of care heparin as the comparator and, as a result, we have no clinical trial data directly comparing REG1 and bivalirudin. The primary efficacy endpoint
of our REGULATE-PCI trial is a 20.0% reduction in the occurrence of ischemic events using REG1 compared to bivalirudin and the primary safety endpoint of the trial is non-inferiority of REG1 compared to bivalirudin with respect to major bleeding
events. Because we have no clinical trial data directly comparing REG1 to bivalirudin, the prediction of Phase 3 success based on Phase 2 results is complicated and the risk that REGULATE-PCI does not achieve one or more of these endpoints
may be increased.

Our product candidates may cause serious adverse events or undesirable side effects which may delay
or prevent marketing approval, or, if approval is received, require them to be taken off the market, require them to include safety warnings or otherwise limit their sales.

Serious adverse events or undesirable side effects from REG1 or any of our other product candidates could arise either during clinical
development or, if approved, after the approved product has been marketed. For example, three severe allergic events occurred in our RADAR trial. In addition, in 2008 we terminated an exploratory Phase 2a trial of REG1 in subjects undergoing
off-pump coronary arterial bypass grafting when the first enrolled subject experienced clotting in one of three bypass grafts. The results of future clinical trials, including REGULATE-PCI, may show that our product candidates cause serious adverse
events or undesirable side effects, which could interrupt, delay or halt clinical trials, resulting in delay of, or failure to obtain, marketing approval from the FDA and other regulatory authorities.

If REG1 or any of our other product candidates cause serious adverse events or undesirable side effects:



regulatory authorities may impose a clinical hold which could result in substantial delays and adversely impact our ability to continue development of
the product;



regulatory authorities may require the addition of labeling statements, specific warnings, a contraindication or field alerts to physicians and
pharmacies;



we may be required to change the way the product is administered, conduct additional clinical trials or change the labeling of the product;



we may be required to implement a risk minimization action plan, which could result in substantial cost increases and have a negative impact on our
ability to commercialize the product;



we may be required to limit the patients who can receive the product;



we may be subject to limitations on how we promote the product;



sales of the product may decrease significantly;



regulatory authorities may require us to take our approved product off the market;



we may be subject to litigation or product liability claims; and



our reputation may suffer.

Any of these events could prevent us from achieving or maintaining market acceptance of the affected product or could substantially increase commercialization costs and expenses, which in turn could delay
or prevent us from generating significant revenues from the sale of our products.

We have limited experience manufacturing the oligonucleotides comprising our product
candidates at commercial scale and there are no established standards for their manufacture. As a result, delays in regulatory approval of our product candidates may occur. Also, manufacturing issues may arise that could cause delays or increase
costs.

We have limited experience manufacturing the oligonucleotides comprising our product candidates at commercial
scale. We, together with our CMOs, have developed manufacturing processes that have never been tested in commercial production. Our manufacturing process will be subject to approval by regulators before we can commence the manufacture and sale of an
approved product. The standards of the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use, which establishes basic guidelines and standards for drug development in the United States,
the European Union, Japan and other countries, do not apply to oligonucleotides, including our product candidates. As a result, there is no established generally accepted manufacturing or quality standard for the production of our product
candidates. Even though the FDA has agreed to the quality standards for the REG1 to be used in our REGULATE-PCI trial, the FDA has the ability to modify those standards at any time and foreign regulatory agencies may impose differing quality
standards and quality control on the manufacture of our drug candidates. The lack of uniform manufacturing and quality standards among regulatory agencies may delay regulatory approval of our product candidates. Also, as we scale-up manufacturing of
any approved product, our CMOs may encounter unexpected issues relating to the manufacturing process or the quality, purity and stability of the product and we may be required to refine or alter our manufacturing processes to address these issues.
Resolving these issues could result in significant delays and may result in significantly increased costs. If we experience significant delays or other obstacles in producing any approved product for commercial scale, our ability to market and sell
any approved products may be adversely affected and our business could suffer.

REG1 and our other product candidates
employ novel mechanisms of action and may never be approved or accepted by their intended markets.

Our activities have
focused on the discovery and development of therapeutic aptamers and their specific active control agents. Our future success depends on our ability to complete the REGULATE-PCI trial of REG1 successfully, obtain market approval for and successfully
commercialize REG1, as well as our ability to develop and market other product candidates that use our proprietary technology platform. We believe only one therapeutic aptamer has been approved for commercial sale and no product candidate consisting
of a therapeutic aptamer and its specific active control agent has ever received regulatory approval. The scientific discoveries that form the basis of our proprietary technology platform and our product candidates are relatively new. We are not
aware of any other antithrombotic drugs that have the same mechanism of action as our product candidates and there can be no assurance that, even if approved, physicians will be willing to use them. If we do not successfully develop and
commercialize product candidates based upon our technological approach, we may not become profitable and the value of our common stock may decline.

In addition, regulatory approval of novel product candidates such as REG1 and our other product candidates manufactured using novel manufacturing processes such as ours can be more expensive and take
longer than for other, more well-known or extensively studied pharmaceutical or biopharmaceutical products, due to our and regulatory agencies lack of experience with them. We believe that the FDA has only approved one aptamer product to date.
This lack of experience may lengthen the regulatory review process, require us to conduct additional studies or clinical trials, increase our development costs, lead to changes in regulatory positions and interpretations, delay or prevent approval
and commercialization of these product candidates or lead to significant post-approval limitations or restrictions.

The novel
nature of REG1 and our other product candidates also means that fewer people are trained in or experienced with product candidates of this type, which may make it difficult to find, hire and retain capable personnel for research, development and
manufacturing positions.

Further, our focus solely on controllable aptamer technology for developing drugs as opposed to
multiple, more proven technologies for drug development increases the risks associated with the ownership of our common

stock. If we do not obtain regulatory approval for REG1 and our other product candidates and achieve market acceptance for our approved products, we may be required to change the scope and
direction of our product development activities. In that case, we may not be able to identify and implement successfully an alternative product development strategy.

Risks Relating to the Commercialization of Our Product Candidates

If
any of our product candidates for which we receive regulatory approval do not achieve broad market acceptance, the revenues that are generated from their sales will be limited.

The commercial success of REG1 and our other product candidates, if approved, will depend upon the acceptance of these products among
physicians, healthcare payors and patients. The degree of market acceptance of our product candidates will depend on a number of factors, including:



limitations or warnings contained in a products FDA-approved labeling;



changes in the standard of care or the availability of alternative therapies for the targeted indications for any of our product candidates;



limitations in the approved indications for our product candidates;



demonstrated clinical safety and efficacy compared to other products;



lack of significant adverse side effects;



education, sales, marketing and distribution support;



availability and degree of reimbursement from third-party payors;



timing of market introduction and perceived effectiveness of competitive products;



cost-effectiveness;



availability of alternative therapies at similar or lower cost, including generics, biosimilar and over-the-counter products;

If our product candidates are approved, but do not achieve an adequate level of acceptance by physicians, healthcare payors and patients, sufficient revenue may not be generated from these products, and
we may not become or remain profitable. In addition, efforts to educate the medical community and third-party payors on the benefits of our product candidates may require significant resources and may never be successful.

REG1 and each of our other product candidates consist of a therapeutic aptamer and its specific active control agent. These two components
are administered at different times and in different strengths and the failure to administer the components correctly may expose a patient to significant risk. Physicians will need to be educated as to our products novel mechanisms of action
and trained as to the proper use of our products. Physicians may be unwilling to devote the time necessary to learn how to use our product candidates properly and may continue using other competing products even if our products are safer and more
effective. As a result, the commercialization of any approved product may be slower than we expect and any approved product may not achieve the level of acceptance we anticipate. If physicians are unwilling to use our products as a result of their
novel mechanisms of action or the need to be trained on their use, our business may suffer.

We do not have the capability to sell, distribute and market our product candidates.
If we are unable to establish an effective sales force and marketing infrastructure, or enter into acceptable third-party sales and marketing or licensing arrangements, we may not be able to commercialize our product candidates successfully.

We do not have the capability to sell, distribute and market our product candidates. We will need to build a
commercial organization or secure a strategic partner to commercialize REG1 or any other product candidates. If we are unable to build a commercial infrastructure or secure a strategic collaboration, our business and results of operations will be
materially and adversely affected. Development of an internal commercial organization will require substantial resources and will be time consuming. These costs may be incurred in advance of any approval of our product candidates. In addition, we
may not be able to hire a sales force in the United States that is sufficient in size or has adequate expertise in the medical markets that we intend to target. If we are unable to establish a sales and marketing capability, our operating results
may be adversely affected. If we seek to enter into sales and marketing or licensing arrangements with third parties for the marketing and sale of any approved products, we may be unable to enter into any such arrangements on acceptable terms, or at
all.

Even if our product candidates receive regulatory approval, we may still face future development and regulatory
difficulties.

Even if regulatory approval is obtained for any of our product candidates, regulatory authorities may
still impose significant restrictions on a products indicated uses or marketing or impose ongoing requirements for potentially costly post-approval studies. Given the number of high profile adverse safety events with certain drug products,
regulatory authorities may require, as a condition of approval, costly REMS, which may include safety surveillance, restricted distribution and use, patient education, enhanced labeling, expedited reporting of certain adverse events, pre-approval of
promotional materials and restrictions on direct-to-consumer advertising. For example, any labeling approved for any of our product candidates may include a restriction on the term of its use, or it may not include one or more of our intended
indications. Furthermore, any new legislation addressing drug safety issues could result in delays or increased costs during the period of product development, clinical trials and regulatory review and approval, as well as increased costs to assure
compliance with any new post-approval regulatory requirements.

Our product candidates will also be subject to ongoing
regulatory requirements for the labeling, packaging, storage, advertising, promotion, record-keeping and submission of safety and other post-market information. In addition, sellers of approved products, manufacturers and manufacturers
facilities are required to comply with extensive FDA requirements, including ensuring that quality control and manufacturing procedures conform to cGMP. As such, we and our CMOs are subject to continual review and periodic inspections to assess
compliance with cGMP. Accordingly, we and others with whom we work must continue to expend time, money, and effort in all areas of regulatory compliance, including manufacturing, production, and quality control. We will also be required to report
certain adverse reactions and production problems, if any, to the FDA, and to comply with certain requirements concerning advertising and promotion for our products. Promotional communications with respect to prescription drugs are subject to a
variety of legal and regulatory restrictions and must be consistent with the information in the products approved label. As such, we may not promote our products for indications or uses for which they do not have approval.

If a regulatory agency discovers previously unknown problems with a product, such as adverse events of unanticipated severity or
frequency, or problems with the facility where the product is manufactured, or disagrees with the promotion, marketing, or labeling of a product, it may impose restrictions on that product or us, including requiring withdrawal of the product from
the market. If our product candidates fail to comply with applicable regulatory requirements, a regulatory agency may:



issue warning or other letters;



mandate modifications to promotional materials or require us to provide corrective information to healthcare practitioners;

require us to enter into a consent decree or permanent injunction, which can include imposition of various fines, reimbursements for inspection costs,
required due dates for specific actions and penalties for noncompliance;



impose other civil or criminal penalties;



suspend or withdraw regulatory approval;



suspend any ongoing clinical trials;



refuse to approve pending applications or supplements to approved applications filed by us;



impose restrictions on operations, including costly new manufacturing requirements; or



seize or detain products or require a product recall.

We expect that our existing and future product candidates will face competition and most of our competitors have significantly greater resources than we do.

The biopharmaceutical industry is characterized by intense competition and rapid innovation. Our potential
competitors include large pharmaceutical and biotechnology companies, specialty pharmaceutical companies and generic or biosimilar drug companies. We believe the key competitive factors that will affect the development and commercial success of our
product candidates are efficacy, safety and tolerability profile, mechanism of action, control and predictability, convenience of dosing and price and reimbursement. Our most advanced product candidate, REG1, is being developed for use in patients
undergoing percutaneous coronary intervention for a wide variety of cardiovascular conditions. If approved for this indication, REG1 would compete with a number of currently-marketed anticoagulants, including bivalirudin, currently marketed and sold
by The Medicines Company under the brand name Angiomax® in the United States, and heparin, or UFH, and low
molecular weight heparin, or LMWH, both of which are available as biosimilars and currently manufactured and sold by multiple manufacturers. Otamixaban, which is being developed by Sanofi, is being evaluated in a Phase 3 clinical trial for patients
with unstable angina and non-ST elevated myocardial infarctions scheduled to undergo an early invasive strategy. If REG1 is approved for this initial indication, we intend to seek approval for the use of REG1 in other cardiovascular indications. If
approved for these additional indications, REG1 would potentially compete with the same treatments described above.

Accordingly, our competitors may be more successful than us in obtaining regulatory approval for drugs and achieving widespread market acceptance. Our competitors drugs may be more effective, or
more effectively marketed and sold, than any product candidate we may commercialize and may render our product candidates obsolete or non-competitive before we can recover the expenses of their development and commercialization. We anticipate that
we will face intense and increasing competition as new drugs enter the market and advanced technologies become available. Finally, the development of new treatment methods for the diseases we are targeting could render our product candidates
non-competitive or obsolete.

Reimbursement decisions by third-party payors may have an adverse effect on pricing
and market acceptance of REG1 or any of our other product candidates. If there is not sufficient reimbursement for our products, it is less likely that our products will be widely used.

Market acceptance and sales of REG1 or any other product candidates that we develop will depend on reimbursement policies and may be
affected by future healthcare reform measures. Government authorities and third-party payors, such as private health insurers and health maintenance organizations, decide which drugs they will cover and establish payment levels. We cannot be certain
that reimbursement will be available for REG1 or any other product candidates that we develop. Also, we cannot be certain that reimbursement policies will not reduce the demand for, or the price paid for, our products. If reimbursement is not
available or is available on a limited basis, we may not be able to successfully commercialize REG1 or any other product candidates that we develop.

In the United States, the Medicare Prescription Drug, Improvement, and Modernization Act of 2003, also called the Medicare Modernization Act, or MMA, changed the way Medicare covers and pays for
pharmaceutical products. The legislation established Medicare Part D, which expanded Medicare coverage for outpatient prescription drug purchases by the elderly but provided authority for limiting the number of drugs that will be covered in any
therapeutic class. The MMA also introduced a new reimbursement methodology based on average sales prices for physician-administered drugs.

The United States and several foreign jurisdictions are considering, or have already enacted, a number of legislative and regulatory proposals to change the healthcare system in ways that could affect our
ability to sell our products profitably. Among policy makers and payors in the United States and elsewhere, there is significant interest in promoting changes in healthcare systems with the stated goals of containing healthcare costs, improving
quality and expanding access to healthcare. In the United States, the pharmaceutical industry has been a particular focus of these efforts and has been significantly affected by major legislative initiatives. We expect to experience pricing
pressures in connection with the sale of REG1 and any other products that we develop, due to the trend toward managed healthcare, the increasing influence of health maintenance organizations and additional legislative proposals.

In March 2010, the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Affordability Reconciliation
Act, or collectively, the Affordable Care Act, became law in the United States. The goal of the Affordable Care Act is to reduce the cost of healthcare and substantially change the way healthcare is financed by both governmental and private
insurers. While we cannot predict what impact on federal reimbursement policies this legislation will have in general or on our business specifically, the Affordable Care Act may result in downward pressure on pharmaceutical reimbursement, which
could negatively affect market acceptance of REG1 or any future product candidates. Members of the U.S. Congress and some state legislatures are seeking to overturn at least portions of the legislation and we expect they will continue to review and
assess this legislation and possibly alternative healthcare reform proposals. We cannot predict whether new proposals will be made or adopted, when they may be adopted or what impact they may have on us if they are adopted.

If we obtain approval to commercialize any approved products outside of the United States, a variety of risks associated with
international operations could materially adversely affect our business.

If REG1 or any of our other product
candidates are approved for commercialization outside of the United States, we intend to enter into agreements with third parties to market them on a worldwide basis or in more limited geographical regions. We expect that we will be subject to
additional risks related to entering into international business relationships, including:

We may not succeed in establishing and maintaining collaborative relationships, which may significantly limit our ability to develop and commercialize our product candidates successfully, if at all.

We intend to seek collaborative relationships for the development and commercialization of our product candidates,
including REG1. Failure to obtain a collaborative relationship for REG1, particularly in the European Union and for other markets requiring extensive sales efforts, may significantly impair the potential for this product candidate. We also will need
to enter into collaborative relationships to provide funding to support our other research and development programs. The process of establishing and maintaining collaborative relationships is difficult, time-consuming and involves significant
uncertainty, including:



a collaboration partner may shift its priorities and resources away from our product candidates due to a change in business strategies, or a merger,
acquisition, sale or downsizing;



a collaboration partner may seek to renegotiate or terminate their relationships with us due to unsatisfactory clinical results, manufacturing issues,
a change in business strategy, a change of control or other reasons;



a collaboration partner may cease development in therapeutic areas which are the subject of our strategic collaboration;

a collaboration partner may change the success criteria for a product candidate thereby delaying or ceasing development of such candidate;



a significant delay in initiation of certain development activities by a collaboration partner will also delay payment of milestones tied to such
activities, thereby impacting our ability to fund our own activities;



a collaboration partner could develop a product that competes, either directly or indirectly, with our product candidate;



a collaboration partner with commercialization obligations may not commit sufficient financial or human resources to the marketing, distribution or
sale of a product;



a collaboration partner with manufacturing responsibilities may encounter regulatory, resource or quality issues and be unable to meet demand
requirements;



a partner may exercise a contractual right to terminate a strategic alliance;

a dispute may arise between us and a partner concerning the research, development or commercialization of a product candidate resulting in a delay in
milestones, royalty payments or termination of an alliance and possibly resulting in costly litigation or arbitration which may divert management attention and resources; and



a partner may use our products or technology in such a way as to invite litigation from a third party.

If any collaborator fails to fulfill its responsibilities in a timely manner, or at all, our research, clinical development,
manufacturing, or commercialization efforts related to that collaboration could be delayed or terminated, or it may be necessary for us to assume responsibility for expenses or activities that would otherwise have been the responsibility of our
collaborator. If we are unable to establish and maintain collaborative relationships on acceptable terms or to successfully transition terminated collaborative agreements, we may have to delay or discontinue further development of one or more of our
product candidates, undertake development and commercialization activities at our own expense or find alternative sources of capital.

We rely on third parties to conduct, supervise and monitor our clinical trials, and if those third parties perform in an unsatisfactory manner, it may harm our business.

We rely on CROs and clinical trial sites to ensure the proper and timely conduct of our clinical trials. While we have
agreements governing their activities, we will have limited influence over their actual performance. We will control only certain aspects of our CROs activities. Nevertheless, we will be responsible for ensuring that our clinical trials are
conducted in accordance with the applicable protocol, legal, regulatory and scientific standards and our reliance on the CROs does not relieve us of our regulatory responsibilities.

We and our CROs are required to comply with the FDAs current good clinical practices requirements, or cGCP, for conducting,
recording and reporting the results of clinical trials to assure that data and reported results are credible and accurate and that the rights, integrity and confidentiality of clinical trial participants are protected. The FDA enforces these cGCPs
through periodic inspections of trial sponsors, principal investigators and clinical trial sites. If we or our CROs fail to comply with applicable cGCPs, the clinical data generated in our clinical trials may be deemed unreliable and the FDA may
require us to perform additional clinical trials before approving any marketing applications. Upon inspection, the FDA may determine that our clinical trials did not comply with cGCPs. In addition, our clinical trials, including our REGULATE-PCI
trial, will require a sufficiently large number of test subjects to evaluate the safety and effectiveness of a product candidate. Accordingly, if our CROs fail to comply with these regulations or fail to recruit a sufficient number of patients, our
clinical trials may be delayed or we may be required to repeat such clinical trials, which would delay the regulatory approval process.

Our CROs are not our employees, and we are not able to control whether or not they devote sufficient time and resources to our clinical trials. These CROs may also have relationships with other commercial
entities, including our competitors, for whom they may also be conducting clinical trials, or other drug development activities which could harm our competitive position. If our CROs do not successfully carry out their contractual duties or
obligations, fail to meet expected deadlines, or if the quality or accuracy of the clinical data they obtain is compromised due to the failure to adhere to our clinical protocols or regulatory requirements, or for any other reasons, our clinical
trials may be extended, delayed or terminated, and we may not be able to obtain regulatory approval for, or successfully commercialize our product candidates. As a result, our financial results and the commercial prospects for such product
candidates would be harmed, our costs could increase, and our ability to generate revenues could be delayed.

We also rely on
other third parties to store and distribute drug products for our clinical trials. Any performance failure on the part of our distributors could delay clinical development or marketing approval of our product candidates or commercialization of our
products, if approved, producing additional losses and depriving us of potential product revenue.

We do not have multiple sources of supply for the components used in REG1 and our
other product candidates. If we were to lose a supplier, it could have a material adverse effect on our ability to complete the development of REG1 or our other product candidates or, if we obtain regulatory approval for REG1 or our other product
candidates, to commercialize them.

We do not have multiple sources of supply for the components used in REG1 and our
other product candidates. We also do not have long-term supply agreements with any of our suppliers. If for any reason we are unable to obtain drug compounds from a supplier, we would have to seek to obtain it from another oligonucleotide
manufacturer. We may not be able to establish additional sources of supply for our product candidates, or may be unable to do so on acceptable terms. Such suppliers are subject to regulatory requirements, covering manufacturing, testing, quality
control and record keeping relating to our product candidates and subject to ongoing inspections by the regulatory agencies. Failure by any of our suppliers to comply with applicable regulations may result in long delays and interruptions.

The number of oligonucleotide suppliers is limited. In the event it is necessary or desirable to acquire supplies from an
alternative supplier, we might not be able to obtain them on commercially reasonable terms, if at all. It could also require significant time and expense to redesign our manufacturing processes to work with another company.

As part of any marketing approval, a manufacturer and its processes are required to be qualified by the FDA prior to commercialization. If
supply from the approved supplier is interrupted, there could be a significant disruption in commercial supply. An alternative vendor would need to be qualified through an NDA supplement which could result in further delay. The FDA or other
regulatory agencies outside of the United States may also require additional studies if a new supplier is relied upon for commercial production. Switching vendors may involve substantial costs and is likely to result in a delay in our desired
clinical and commercial timelines.

If we are unable to obtain the supplies we need at a reasonable price or on a timely basis,
it could have a material adverse effect on our ability to complete the development of REG1 and our other product candidates or, if we obtain regulatory approval for REG1 or our other product candidates, to commercialize them.

We rely on third-party manufacturers to produce our product candidates. If we experience problems with any of these suppliers, the
manufacturing of our product candidates or products could be delayed.

We do not have the capability to manufacture our
product candidates and do not intend to develop that capability. As a result, we rely on CMOs to produce our product candidates. If REG1 or our other product candidates are approved for sale, we expect to enter into contracts with CMOs for the
commercial scale production of the approved product. Reliance on CMOs entails risks, including:

operations of our CMOs or suppliers could be disrupted by conditions unrelated to our business or operations, including the bankruptcy of the CMO or
supplier;

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carrier disruptions or increased costs that are beyond our control; and

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the failure to deliver products under specified storage conditions and in a timely manner.

Any of these risks could cause the delay of clinical trials, regulatory submissions, required approvals or commercialization of our
products, cause us to incur higher costs and prevent us from commercializing our product candidates successfully. Manufacturing of our product candidates and any approved products could be disrupted or halted if our CMOs do not comply with cGMP or
foreign manufacturing standards, even if the compliance failure does not relate to our product candidates or approved products. Furthermore, if any of our product candidates are approved and our CMOs fail to deliver the required commercial
quantities of finished product on a timely basis and at commercially reasonable prices and we are unable to find one or more replacement manufacturers capable of production at a substantially equivalent cost, in substantially equivalent volumes and
quality and on a timely basis, we would likely be unable to meet demand for our products and could lose potential revenue. It may take several years to establish an alternative source of supply for our product candidates and to have any such new
source approved by the FDA or a foreign regulator.

Risks Relating to Our Intellectual Property

It is difficult and costly to protect our proprietary rights, and we may not be able to ensure their protection.

Our commercial success will depend in part on obtaining and maintaining proprietary rights important to our business, as well as
successfully defending and enforcing those proprietary rights if challenged. The procurement, defense and enforcement of intellectual property rights involve complex legal and factual questions. Changes in either the patent laws or in
interpretations of patent laws in the United States and foreign jurisdictions may diminish the value of our intellectual property. Laws relating to patent rights continue to evolve in the United States and foreign jurisdictions, as does their
interpretation by national patent offices and judicial systems, creating some uncertainty for patent applicants, patent owners and licensees.

Our ability to stop third parties from using our technology or making, using, selling, offering to sell or importing our products is dependent upon the extent to which we have rights under valid and
enforceable patents or trade secrets that cover these activities. If any patent we currently or in the future may own or license is deemed invalid or unenforceable, it could impact our commercial success. We cannot predict the breadth of claims that
may be issued from any patent applications we currently or may in the future own or license from third parties.

The degree of
future protection our proprietary rights may afford is uncertain because legal means afford only limited protection and may not adequately protect our rights or permit us to gain or keep our competitive advantage. For example:

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others may be able to make, use, sell, offer to sell or import products that are similar to our product candidates but that are not covered by the
claims of our patents;

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we might not have been the first to make the inventions covered by our patent portfolio;

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we might not have been the first to file patent applications for these inventions;

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others may independently develop similar or alternative technologies or duplicate any of our technologies in a manner that does not violate our trade
secrets;

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our proprietary rights may not provide us with any competitive advantages;

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we may not develop additional technologies or products that are patentable or suitable to maintain as trade secrets; or

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the proprietary rights of others may have an adverse effect on our business.

As of April 29, 2013, we are the owner of record of five issued or allowed U.S. patents and six issued or allowed non-U.S. patents, as
well as the licensee of at least nine issued or allowed U.S. patents and at least ten

issued or allowed non-U.S. patents. We are actively pursuing an additional 13 U.S. patent applications, of which four are provisional and nine are non-provisional, one international patent
application and 39 non-U.S. patent applications in twelve jurisdictions as the owner of record, in addition to at least two U.S. patent applications and 14 non-U.S. patent applications under license.

We also may rely on trade secrets to protect our technology, especially where we do not believe patent protection is appropriate or
obtainable. Our ability to stop third parties from making, using, selling, offering to sell or importing our products or practicing our technology is dependent in part upon the extent to which we have rights in enforceable trade secrets that cover
these activities. Trade secret rights can be lost through disclosure to third parties. Although we use reasonable efforts to protect our trade secrets, our employees, consultants, contractors, outside scientific collaborators and other advisors may
unintentionally or willfully disclose our trade secrets to third parties, resulting in loss of trade secret protection. Moreover, our competitors may independently develop equivalent knowledge, methods and know-how, which would not constitute a
violation of our trade secret rights. Enforcing a claim that a third party is engaged in the unlawful use of our trade secrets is expensive and time consuming, and the outcome is unpredictable. In addition, recognition of rights in trade secrets and
a willingness to enforce trade secrets may differ in certain jurisdictions.

Intellectual property disputes are
expensive and would consume time and resources and divert the attention of managerial and scientific personnel. We may incur substantial costs as a result of litigation or other proceedings relating to patent and other intellectual property rights
and we may be unable to enforce or protect our rights to, or use, our technology.

If we choose to go to court to
attempt to stop another party from using our intellectual property without authorization, or any licensor of our intellectual property chooses to do the same, rights in our intellectual property may be lost. More specifically, rights in trade
secrets we have or obtain may be lost as the result of disclosure associated with of our efforts to stop their unauthorized use. Rights in any patents we have or obtain may be lost as a result of our efforts to stop their unauthorized use, as the
party charged with patent infringement has the right to ask the court to rule that such patents are invalid or should not be enforced against that third party. There is also the risk that, even if the validity of such patents is upheld, the court
will refuse to stop the other party on the ground that such other partys activities do not infringe our rights to such patents. Apart from litigation, adversarial procedures are available in the patent offices of many countries, including the
United States, that permit interested third parties to dispute the validity of issued patents or to otherwise impact the course of prosecution of pending patent applications. Intellectual property disputes are expensive and would consume time and
resources and divert the attention of managerial and scientific personnel even if we were successful in stopping the unauthorized use of our intellectual property rights. Moreover, the patent laws in the United States and internationally continue to
evolve, creating uncertainty as to the likelihood that we will be able to obtain patents and increase the likelihood of challenge to any patents we obtain or license.

Furthermore, a third party may claim that we or our manufacturing partners are engaged in unauthorized use of intellectual property owned by the third party, including patent rights, and may go to court
to stop us from engaging in our normal operations and activities, including making or selling our product candidates. These lawsuits are costly and could affect our results of operations and divert the attention of managerial and scientific
personnel. There is a risk that a court would decide that we or our CMOs are engaged in unauthorized use of the third partys valid and enforceable intellectual property, including patent rights, and would order us or our CMOs to stop the
activities protected by these rights. In that event, we may not have a viable alternative to the unauthorized use and may need to halt commercialization of the relevant product. In addition, there is a risk that a court will order us or our CMOs to
pay the other party damages for having used the other partys intellectual property in an unauthorized manner. In the future, we may agree to indemnify our CMOs against certain intellectual property claims brought by third parties. Patent
rights involve complex factual and legal issues; as a result, it is not always clear to industry participants, including us, whether activities or products are covered by patent rights, or by which patent rights. The breadth of patent claims is
subject to interpretation by the courts, and the interpretation is not always uniform. If we are sued for patent infringement, we would need to demonstrate that our products or methods either do not infringe the claims of the relevant patents or
that the patent claims are

invalid, and we may not be able to do this. Proving invalidity is difficult. For example, in the United States, proving invalidity requires the alleged infringer to overcome the presumption of
validity enjoyed by issued patents.

Because some patent applications may be maintained in secrecy until the patents are
issued, publication of patent applications is delayed, and publications in the scientific literature often lag behind actual discoveries, we cannot be certain that others have not filed patent applications for technology covered by our pending
applications, or that we were the first to invent the technology. Our competitors may have filed, and may in the future file, patent applications covering technology important to our business. Any such patent application may have priority over our
patent applications, which could further require us to obtain rights to issued patents covering such technologies and serve as a bar to patentability of our own patent filings. If another party has filed a U.S. patent application on inventions
similar to ours, we may have to participate in an interference proceeding declared by the U.S. Patent and Trademark Office to determine priority of invention in the United States. The costs of these proceedings could be substantial, and it is
possible that such efforts would be unsuccessful if, unbeknownst to us, the other party had independently arrived at the same or similar invention prior to our own invention, resulting in a loss of our U.S. patent position with respect to such
invention.

Some of our competitors may be able to sustain the costs of patent-related disputes, including patent litigation,
more effectively than we can because they have substantially greater resources. In addition, any uncertainties resulting from the initiation and continuation of any litigation could have a material adverse effect on our ability to raise the funds
necessary to continue our operations.

Risks Related to Employee Matters and Managing Growth

We will need to expand our operations and increase the size of our company, and we may experience difficulties in managing growth.

As we advance our product candidates through preclinical studies and clinical trials and develop new product
candidates, we will need to increase our product development, scientific and administrative headcount to manage these programs. In addition, to meet our obligations as a public company, we will need to increase our general and administrative
capabilities. Our management, personnel and systems currently in place may not be adequate to support this future growth. Our need to effectively manage our operations, growth and various projects requires that we:

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successfully attract and recruit new employees with the expertise and experience we will require;

If we are unable to successfully manage this growth and increased complexity of operations, our business may be adversely affected.

We may not be able to manage our business effectively if we are unable to attract and retain key personnel.

We may not be able to attract or retain qualified management, finance, scientific and clinical personnel in the future
due to the intense competition for qualified personnel among biotechnology, pharmaceutical and other businesses. If we are not able to attract and retain necessary personnel to accomplish our business objectives, we may experience constraints that
will significantly impede the achievement of our development objectives, our ability to raise additional capital and our ability to implement our business strategy.

Our industry has experienced a high rate of turnover of management personnel in recent years. We are highly dependent on the development, regulatory, commercialization and business development expertise
of our executive officers and key employees identified in the Management section of this prospectus. If we lose one

or more of our executive officers or key personnel, our ability to implement our business strategy successfully could be seriously harmed. Any of our executive officers or key employees may
terminate their employment at any time. We have entered into change of control and severance agreements with certain of our officers as part of our retention efforts. The terms of these agreements are described in the Executive and Director
Compensation  Employment Agreements, Severance and Change in Control Agreements section of this prospectus. Replacing executive officers and key employees may be difficult, will be costly and may take an extended period of time because
of the limited number of individuals in our industry with the mix of skills and experience required to develop, gain regulatory approval of and commercialize products successfully. Competition to hire from this limited pool is intense, and we may be
unable to hire, train, retain or motivate these additional key personnel. Our failure to attract and retain key personnel could materially harm our business.

As a public company, we will operate in an increasingly demanding regulatory environment,
which requires us to comply with applicable provisions of the Sarbanes-Oxley Act of 2002, or Sarbanes-Oxley Act, and the related rules and regulations of the Securities and Exchange Commission, expanded disclosure requirements, accelerated reporting
requirements and more complex accounting rules. Company responsibilities required by the Sarbanes-Oxley Act include establishing corporate oversight and adequate internal control over financial reporting and disclosure controls and procedures.
Effective internal controls are necessary for us to produce reliable financial reports and are important to help prevent financial fraud.

We rely on consultants to perform certain of our accounting and financial reporting functions. We will need to hire additional finance personnel and build our financial infrastructure as we transition to
operating as a public company, including complying with the applicable requirements of Section 404 of the Sarbanes-Oxley Act. We may be unable to do so on a timely basis.

Until we are able to expand our finance and administrative capabilities and establish necessary financial reporting infrastructure, we may not be able to prepare and disclose, in a timely manner, our
financial statements and other required disclosures or comply with the applicable provisions of the Sarbanes-Oxley Act or existing or new reporting requirements. If we cannot provide reliable financial reports or prevent fraud, our business and
results of operations could be harmed and investors could lose confidence in our reported financial information.

We
have had a material weakness in our internal control over financial reporting.

We have not been a public reporting
company and have had limited accounting personnel and systems to adequately execute accounting processes and limited other supervisory resources with which to address internal control over financial reporting. As such, we have identified past
accounting errors, which resulted in the restatement of our previously issued financial statements. We and our independent registered public accounting firm identified a material weakness in internal control over financial reporting related to these
items which required adjustment, specifically: (i) accounting for the purchase of supplies used in the production of our drug product, and (ii) accounting for purchase orders related to manufacturing services where work was contracted but
not yet performed. Under standards established by the Public Company Accounting Oversight Board, a deficiency in internal control over financial reporting exists when the design or operation of a control does not allow management or personnel, in
the normal course of performing their assigned functions, to prevent or detect misstatements on a timely basis. A material weakness is a deficiency or combination of deficiencies in internal control over financial reporting, such that there is a
reasonable possibility that a material misstatement of our annual or interim financial statements will not be prevented or detected and corrected on a timely basis. We are in the process of remediating the material weakness identified by us and our
independent registered public accounting firm; however, we cannot assure that there will not be additional material weaknesses and significant deficiencies that our independent registered public accounting firm or we will identify. If we identify
such issues or if we are unable to produce accurate and timely financial statements, our stock price may be adversely affected and we may be unable to maintain compliance with applicable securities laws and listing requirements.

Our employees may engage in misconduct or other improper activities, including
noncompliance with regulatory standards and requirements and insider trading.

We are exposed to the risk of employee
fraud or other misconduct. Misconduct by employees could include intentional failures to comply with the regulations of the FDA and non-U.S. regulators, provide accurate information to the FDA and non-U.S. regulators, comply with healthcare fraud
and abuse laws and regulations in the United States and abroad, report financial information or data accurately or disclose unauthorized activities to us. In particular, sales, marketing and business arrangements in the healthcare industry are
subject to extensive laws and regulations intended to prevent fraud, misconduct, kickbacks, self-dealing and other abusive practices. These laws and regulations may restrict or prohibit a wide range of pricing, discounting, marketing and promotion,
sales commission, customer incentive programs and other business arrangements. Employee misconduct could also involve the improper use of information obtained in the course of clinical trials, which could result in regulatory sanctions and cause
serious harm to our reputation. We have adopted a code of conduct, but it is not always possible to identify and deter employee misconduct, and the precautions we take to detect and prevent this activity may not be effective in controlling unknown
or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to comply with these laws or regulations. If any such actions are instituted against us, and we are not successful
in defending ourselves or asserting our rights, those actions could have a significant impact on our business, including the imposition of significant fines or other sanctions.

Other Risks Relating to Our Business

We may use our financial and
human resources to pursue a particular research program or product candidate and fail to capitalize on programs or product candidates that may be more profitable or for which there is a greater likelihood of success.

Because we have limited financial and human resources, we intend to focus on the regulatory approval of REG1, including the completion of
the REGULATE-PCI trial. As a result, we may forego or delay pursuit of opportunities with other product candidates or for other indications that later prove to have greater commercial potential. Our resource allocation decisions may cause us to fail
to capitalize on viable commercial products or profitable market opportunities. Our spending on existing and future product candidates for specific indications may not yield any commercially viable products. If we do not accurately evaluate the
commercial potential or target market for a particular product candidate, we may relinquish valuable rights to that product candidate through strategic alliance, licensing or other royalty arrangements in cases in which it would have been more
advantageous for us to retain sole development and commercialization rights to such product candidate, or we may allocate internal resources to a product candidate in a therapeutic area in which it would have been more advantageous to enter into a
partnering arrangement.

We face potential product liability exposure, and if successful claims are brought against us,
we may incur substantial liability and may have to limit development of a product candidate or commercialization of an approved product.

The use of our product candidates in clinical trials and the sale of any products for which we may obtain marketing approval expose us to the risk of product liability claims. Product liability claims may
be brought against us or our CMOs by participants enrolled in our clinical trials, patients, healthcare providers or others using, administering or selling our products. If we cannot successfully defend ourselves against any such claims, we would
incur substantial liabilities. Regardless of merit or eventual outcome, product liability claims may result in:

diversion of management and scientific resources from our business operations; and

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the inability to commercialize an approved product.

We have obtained limited product liability insurance coverage for our clinical trials domestically and in selected foreign countries where we are conducting clinical trials. Our products liability
insurance coverage is currently limited to $10.0 million per occurrence and $10.0 million in the aggregate per year. As such, our insurance coverage may not reimburse us or may not be sufficient to reimburse us for any expenses or losses
we may suffer. Moreover, insurance coverage is becoming increasingly expensive, and, in the future, we may not be able to maintain insurance coverage at a reasonable cost or in sufficient amounts to protect us against losses due to product
liability. We intend to expand our insurance coverage for products to include the sale of commercial products if we obtain marketing approval for our product candidates, but we may be unable to obtain commercially reasonable product liability
insurance for any products approved for marketing. Large judgments have been awarded in class action lawsuits based on drugs that had unanticipated side effects. A successful product liability claim or series of claims brought against us,
particularly if judgments exceed our insurance coverage, could cause our stock price to decline and could adversely affect our results of operations and business.

Our operations involve hazardous materials, which could subject us to significant liabilities.

Our research and development processes involve the controlled use of hazardous materials. Our operations produce hazardous waste products. We cannot eliminate the risk of accidental contamination or
discharge or injury from these materials. Federal, state and local laws and regulations govern the use, manufacture, storage, handling and disposal of these materials. We could be subject to civil damages in the event of exposure of individuals to
hazardous materials. In addition, claimants may sue us for injury or contamination that results from our use of these materials and our liability may exceed our total assets. We have general liability insurance of up to $1.0 million per
occurrence, with an annual aggregate limit of $2.0 million, which excludes pollution liability. This coverage may not be adequate to cover all claims related to our hazardous materials. Furthermore, if we were to be held liable for a claim involving
hazardous materials, this liability could exceed our insurance coverage, if any, and our other financial resources. Compliance with environmental and other laws and regulations may be expensive and current or future regulations may impair our
research, development or production efforts.

Our insurance policies are expensive and protect us only from some
business risks, which will leave us exposed to significant uninsured liabilities.

We do not carry insurance for all
categories of risk that our business may encounter. Some of the policies we currently maintain include general liability, employment practices liability, property, auto, workers compensation, products liability and directors and
officers insurance. We also expect that operating as a public company will make it more difficult and more expensive for us to obtain director and officer liability insurance, and we may be required to accept reduced policy limits and coverage
or incur substantially higher costs to obtain the same or similar coverage. As a result, it may be more difficult for us to attract and retain qualified people to serve on our board of directors, our board committees or as executive officers. We do
not know, however, if we will be able to maintain existing insurance with adequate levels of coverage. Any significant uninsured liability may require us to pay substantial amounts, which would adversely affect our cash position and results of
operations.

Risks Relating to this Offering and Ownership of Our Common Stock

After this offering, our executive officers, directors and principal stockholders will have the ability to control all matters
submitted to our stockholders for approval.

When this offering is completed, our executive officers, directors and
stockholders who beneficially owned more than 5% of our common stock before this offering will, in the aggregate, beneficially own shares representing 64.9% of our common stock, excluding any shares of our common stock that these stockholders

may purchase in this offering and excluding any shares of common stock underlying option grants to be effective upon closing of this offering. As a result, if these stockholders were to choose to
act together, they would be able to control all matters submitted to our stockholders for approval, as well as our management and affairs. For example, these persons, if they choose to act together, will control the election of directors and
approval of any merger, consolidation, sale of all or substantially all of our assets or other business combination or reorganization. This concentration of voting power could delay or prevent an acquisition of us on terms that other stockholders
may desire. The interests of this group of stockholders may not always coincide with your interests or the interests of other stockholders and they may act in a manner that advances their best interests and not necessarily those of other
stockholders, including seeking a premium value for their common stock, and might affect the prevailing market price for our common stock.

We do not anticipate paying cash dividends on our common stock, and accordingly, stockholders must rely on stock appreciation for any return on their investment.

We have never declared or paid any cash dividend on our common stock and do not anticipate paying cash dividends on our common stock in
the future. Our credit agreement with Comerica Bank prohibits us from paying cash dividends. As a result, the only return to stockholders will be appreciation in the price of our common stock, which may never occur. Investors seeking cash dividends
should not invest in our common stock.

Our share price may be volatile, which could subject us to securities class
action litigation and prevent you from being able to sell your shares at or above the offering price.

The initial
public offering price for our shares will be determined by negotiations between us and the representatives of the underwriters and may not be indicative of prices that will prevail in the trading market. The market price of shares of our common
stock could be subject to wide fluctuations in response to many risk factors listed in this section, and others beyond our control, including:

Furthermore, the stock markets have experienced extreme price and volume fluctuations that
have affected and continue to affect the market prices of equity securities of many companies. These fluctuations often have been unrelated or disproportionate to the operating performance of those companies. These broad market and industry
fluctuations, as well as general economic, political and market conditions such as recessions, interest rate changes or international currency fluctuations, may negatively impact the market price of shares of our common stock. In addition, such
fluctuations could subject us to securities class action litigation, which could result in substantial costs and divert our managements attention from other business concerns, which could potentially harm our business. If the market price of
shares of our common stock after this offering does not exceed the initial public offering price, you may not realize any return on your investment in us and may lose some or all of your investment.

We may be subject to securities litigation, which is expensive and could divert management attention.

Our share price may be volatile, and in the past companies that have experienced volatility in the market price of their stock have been
subject to an increased incidence of securities class action litigation. We may be the target of this type of litigation in the future. Securities litigation against us could result in substantial costs and divert our managements attention
from other business concerns, which could seriously harm our business.

No public market for our common stock currently
exists and an active trading market may not develop or be sustained following this offering.

Prior to this offering,
there has been no public market for our common stock. An active trading market may not develop following the completion of this offering or, if developed, may not be sustained. The lack of an active market may impair your ability to sell your shares
at the time you wish to sell them or at a price that you consider reasonable. The lack of an active market may also reduce the fair market value of your shares. An inactive market may also impair our ability to raise capital to continue to fund
operations by selling shares and may impair our ability to acquire other companies or technologies by using our shares as consideration.

If securities or industry analysts do not publish research or reports about our business, or publish negative reports about our business, our stock price and trading volume could decline.

The trading market for our common stock will depend in part on the research and reports that securities or industry
analysts publish about us or our business. We do not have any control over these analysts. There can be no assurance that analysts will cover us or provide favorable coverage. If one or more of the analysts who cover us downgrade our stock or change
their opinion of our stock, our stock price would likely decline. If one or more of these analysts cease coverage of our company or fail to regularly publish reports on us, we could lose visibility in the financial markets, which could cause our
stock price or trading volume to decline.

A significant portion of our total outstanding shares of common stock is
restricted from immediate resale but may be sold into the market in the near future. This could cause the market price of our common stock to drop significantly, even if our business is doing well.

Sales of a substantial number of shares of our common stock in the public market could occur in the future. These sales, or the perception
in the market that the holders of a large number of shares of common stock intend to sell shares, could reduce the market price of our common stock. After this offering, we will have 14,618,039 outstanding shares of common stock. Of these shares,
5,057,676 may be resold in the public market immediately and the remaining 9,560,363 shares are currently restricted under securities laws or as a result of lock-up agreements but will be able to be resold after the offering as described in the
Shares Eligible for Future Sale section of this prospectus. Moreover, after this offering, holders of an aggregate of 9,396,767 shares of our common stock will have rights, subject to some conditions, to require us to file registration
statements covering their shares or to include their shares in registration statements that we may file for ourselves or other stockholders. We also intend to register up to 3,089,022 shares of common stock that we may issue under our equity
compensation plans. Once we register these shares, they can be freely sold in the public market upon issuance and once vested, subject to the 180 day lock-up periods under the lock-up agreements described in the Underwriting section
of this prospectus.

Purchasers in this offering will experience immediate and substantial dilution in the
book value of their investment.

The initial public offering price of the shares offered by this prospectus will be
substantially higher than the pro forma as adjusted net tangible book value per share of our common stock based on the total value of our tangible assets less our total liabilities immediately following this offering. Therefore, if you purchase
shares of our common stock in this offering, you will experience immediate and substantial dilution of approximately $9.21 per share in the price you pay for shares of our common stock as compared to the pro forma as adjusted net tangible book
value per share, based on an assumed initial public offering price of $15.00 per share (the midpoint of the price range set forth on the cover page of this prospectus). To the extent outstanding options to purchase shares of common stock are
exercised, there will be further dilution. Investors who purchase shares in this offering will contribute approximately 36.0% of the total amount of equity capital raised by us through the date of this offering, but will only own approximately 34.8%
of the shares outstanding immediately following the completion of this offering. For further information on this calculation, see Dilution elsewhere in this prospectus.

Future sales and issuances of our common stock or rights to purchase common stock, including pursuant to our equity incentive
plans, could result in additional dilution of the percentage ownership of our stockholders and could cause our stock price to fall.

We expect that significant additional capital will be needed in the future to continue our planned operations. To the extent we raise additional capital by issuing equity securities, our stockholders may
experience substantial dilution. We may sell common stock, convertible securities or other equity securities. If we sell common stock, convertible securities or other equity securities, your investment in our common stock will be diluted. These
sales may also result in material dilution to our existing stockholders, and new investors could gain rights superior to our existing stockholders.

We have broad discretion in the use of net proceeds from this offering and may not use them effectively.

Our management will have broad discretion in the application of the net proceeds from this offering, including for any of the purposes described in the section entitled Use of Proceeds, and
you will not have the opportunity as part of your investment decision to assess whether the net proceeds are being used appropriately. Because of the number and variability of factors that will determine our use of the net proceeds from this
offering, their ultimate use may vary substantially from their intended use. The failure by our management to apply these funds effectively could harm our business. Pending their use, we may invest the net proceeds from this offering in short-term,
investment-grade, interest-bearing securities. These investments may not yield a favorable return to our stockholders.

We are an emerging growth company, and will be able take advantage of reduced disclosure requirements applicable to
emerging growth companies, which could make our common stock less attractive to investors.

We are an
emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012, or JOBS Act, and, for as long as we continue to be an emerging growth company, we intend to take advantage of certain exemptions from
various reporting requirements applicable to other public companies but not to emerging growth companies, including, but not limited to, not being required to comply with the auditor attestation requirements of Section 404 of the
Sarbanes-Oxley Act, reduced disclosure obligations regarding executive compensation in our periodic reports and proxy statements, and exemptions from the requirements of holding a nonbinding advisory vote on executive compensation and stockholder
approval of any golden parachute payments not previously approved. We could be an emerging growth company for up to five years, or until the earliest of (i) the last day of the first fiscal year in which our annual gross revenues
exceed $1 billion, (ii) the date that we become a large accelerated filer as defined in Rule 12b-2 under the Exchange Act, which would occur if the market value of our common stock that is held by non-affiliates exceeds $700 million
as of the last business day of our most recently completed second fiscal quarter, or (iii) the date on which we have issued

more than $1 billion in non-convertible debt during the preceding three year period. We cannot predict if investors will find our common stock less attractive if we choose to rely on these
exemptions. If some investors find our common stock less attractive as a result of any choices to reduce future disclosure, there may be a less active trading market for our common stock and our stock price may be more volatile.

We will incur significantly increased costs and devote substantial management time as a result of operating as a public company
particularly after we are no longer an emerging growth company.

As a public company, we will incur
significant legal, accounting and other expenses that we did not incur as a private company. For example, we will be required to comply with certain of the requirements of the Sarbanes-Oxley Act and the Dodd-Frank Wall Street Reform and Consumer
Protection Act, as well as rules and regulations subsequently implemented by the Securities and Exchange Commission, and The NASDAQ Global Market, our stock exchange, including the establishment and maintenance of effective disclosure and financial
controls and changes in corporate governance practices. We expect that compliance with these requirements will increase our legal and financial compliance costs and will make some activities more time consuming and costly. In addition, we expect
that our management and other personnel will need to divert attention from operational and other business matters to devote substantial time to these public company requirements. In particular, we expect to incur significant expenses and devote
substantial management effort toward ensuring compliance with the requirements of Section 404 of the Sarbanes-Oxley Act. In that regard, we currently do not have an internal audit function, and we will need to hire additional accounting and
financial staff with appropriate public company experience and technical accounting knowledge.

However, for as long as we
remain an emerging growth company as defined in the JOBS Act, we intend to take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth
companies including, but not limited to, not being required to comply with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act, reduced disclosure obligations regarding executive compensation in our periodic
reports and proxy statements, and exemptions from the requirements of holding a nonbinding advisory vote on executive compensation and stockholder approval of any golden parachute payments not previously approved. We intend to take advantage of
these reporting exemptions until we are no longer an emerging growth company.

Under the JOBS Act, emerging
growth companies can delay adopting new or revised accounting standards until such time as those standards apply to private companies. We have irrevocably elected not to avail ourselves of this exemption from new or revised accounting
standards and, therefore, we will be subject to the same new or revised accounting standards as other public companies that are not emerging growth companies.

After we are no longer an emerging growth company, we expect to incur additional management time and cost to comply with the more stringent reporting requirements applicable to companies that
are deemed accelerated filers or large accelerated filers, including complying with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act.

We cannot predict or estimate the amount of additional costs we may incur as a result of becoming a public company or the timing of such costs.

Anti-takeover provisions in our charter documents and under Delaware law could make an acquisition of our company, which may be
beneficial to our stockholders, more difficult and may prevent attempts by our stockholders to replace or remove our current management.

Provisions in our amended and restated certificate of incorporation and our amended and restated bylaws, both of which will become effective upon the completion of this offering, may delay or prevent a
merger, acquisition or other change of control that stockholders may consider favorable, including transactions in which you might otherwise receive a premium for your shares. These provisions include:

authorizing the issuance of blank check convertible preferred stock, the terms of which may be established and shares of which may be
issued without stockholder approval;



limiting the removal of directors by the stockholders;



requiring a supermajority vote of stockholders to amend our certificate of incorporation or bylaws;



prohibiting stockholder action by written consent, thereby requiring all stockholder actions to be taken at a meeting of our stockholders;



eliminating the ability of stockholders to call a special meeting of stockholders;



establishing advance notice requirements for nominations for election to the board of directors or for proposing matters that can be acted upon at
stockholder meetings; and



establishing Delaware as the exclusive jurisdiction for certain stockholder litigation against us.

In addition, these provisions may frustrate or prevent any attempts by our stockholders to replace or remove our current management by
making it more difficult for stockholders to replace members of our board of directors, who are responsible for appointing the members of our management team. In addition, we are governed by the provisions of Section 203 of the Delaware General
Corporation Law, which prohibits, with some exceptions, stockholders owning in excess of 15% of our outstanding voting stock from merging or combining with us. Although we believe these provisions together provide for an opportunity to receive
higher bids by requiring potential acquirers to negotiate with our board of directors, they would apply even if the offer may be considered beneficial by some stockholders.

This prospectus contains forward-looking statements. All statements other than statements of historical facts contained in
this prospectus, including statements regarding the timing of our clinical trials, our strategy, future operations, future financial position, future revenue, projected costs, prospects, plans, objectives of management and expected market growth are
forward-looking statements. The forward-looking statements are contained principally in the sections entitled Prospectus Summary, Risk Factors, Use of Proceeds, Managements Discussion and Analysis of
Financial Condition and Results of Operations and Business. These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially
different from any future results, performance or achievements expressed or implied by the forward-looking statements.

our ability to satisfy domestic and international regulatory requirements with respect to REG1 and our other product candidates, many of which are new
and still evolving, and the labeling under any approval we may obtain;



the performance of contract research organizations who conduct our clinical trials for us;



the performance of third-party manufacturers who supply or manufacture our products;



our ability to develop commercialization and marketing capabilities or to enter into strategic partnerships to develop and commercialize REG1 or any of
our other product candidates;



the timing and success of the commercialization of REG1 or any of our other product candidates;



the rate and degree of market acceptance of REG1;



the size and growth of the potential markets for REG1 and our ability to serve those markets;

These statements reflect our views with respect to future events as of the date of this
prospectus and are based on assumptions and subject to risks and uncertainties. Given these uncertainties, you should not place undue reliance on these forward-looking statements. These forward-looking statements represent our estimates and
assumptions only as of the date of this prospectus and, except as required by law, we undertake no obligation to update or review publicly any forward-looking statements, whether as a result of new information, future events or otherwise after the
date of this prospectus. We anticipate that subsequent events and developments will cause our views to change. You should read this prospectus and the documents referenced in this prospectus and filed as exhibits to the registration statement, of
which this prospectus is a part, completely and with the understanding that our actual future results may be materially different from what we expect. Our forward-looking statements do not reflect the potential impact of any future acquisitions,
merger, dispositions, joint ventures or investments we may undertake. We qualify all of our forward-looking statements by these cautionary statements.

We estimate that we will receive net proceeds of approximately $68.3 million from our sale of common stock in this offering, or
approximately $78.7 million if the underwriters exercise their overallotment option in full, based on an assumed initial public offering price of $15.00 per share (the midpoint of the price range set forth on the cover page of this prospectus) and
after deducting the estimated underwriting discount and estimated offering expenses payable by us.

A $1.00 increase (decrease)
in the assumed initial public offering price of $15.00 per share would increase (decrease) the net proceeds from this offering by approximately $4.7 million, assuming that the number of shares we are offering, as set forth on the cover page of this
prospectus, remains the same, after deducting the estimated underwriting discount and estimated offering expenses payable by us. We may also increase or decrease the number of shares we are offering. Each increase (decrease) of 1,000,000 shares in
the number of shares we are offering would increase (decrease) the net proceeds to us from this offering by approximately $14.0 million, assuming that the assumed initial public offering price remains the same, and after deducting the estimated
underwriting discount and estimated offering expenses payable by us.

The principal purposes of this offering are to obtain
additional capital to fund our single, open-label, 13,200 subject Phase 3 trial of REG1, or the REGULATE-PCI trial, and to support our operations, to create a public market for our common stock and to facilitate our future access to the public
equity markets. We currently intend to use approximately $67.0 million of the net proceeds from this offering for the REGULATE-PCI trial and the balance to fund working capital and to support our operations.

The amounts and timing of our actual expenditures may vary significantly depending on numerous factors, including:



the timing of the REGULATE-PCI trial;



any delays in the achievement of the interim milestones for the REGULATE-PCI trial;



the extent to which the U.S. Food and Drug Administration may require us to perform additional clinical trials for REG1;



the scope, progress, results and costs of development for additional indications for REG1 and for our other product candidates;



the extent to which we establish collaboration, co-promotion, distribution and other similar agreements for REG1 or our other product candidates;



the extent to which we acquire or invest in products, businesses and technologies;



the costs of obtaining, maintaining, defending and enforcing intellectual property claims; and



any unforeseen or underestimated cash needs.

Therefore, as of the date of this prospectus, we cannot specify with certainty all of the particular uses for the net proceeds to be received upon the completion of this offering. Accordingly, we will
have broad discretion in the application of the net proceeds, and investors will be relying on our judgment regarding the application of the proceeds of this offering.

We believe that the net proceeds of this offering will be sufficient for us to fund the REGULATE-PCI trial through the interim analysis at 50% enrollment, which we expect will occur by the end of 2014. It
is possible that we will not achieve the progress that we expect with respect to REG1 because the actual costs and timing of conducting a large Phase 3 clinical trial are difficult to predict and are subject to substantial risks and delays. Upon the
consummation of this offering, we will have no committed external sources of funds. The expected net proceeds of this offering will not be sufficient for us to complete the REGULATE-PCI trial and we will need to raise substantial additional capital
to complete the development and commercialization of REG1. We also will need to raise additional capital in the future to complete the development and commercialization of REG1 for

additional indications and for our other product candidates. As a result, we will need to finance our future cash needs through public or private equity offerings, debt financings, corporate
collaboration and licensing arrangements or other financing alternatives.

Pending our use of the net proceeds from this
offering, we intend to invest the net proceeds in a variety of capital preservation investments, including short-term, investment-grade, interest-bearing instruments and U.S. government securities.

We have never declared or paid any cash dividends on our common stock, and currently do not plan to declare cash dividends on shares of
our common stock in the foreseeable future. We expect that we will retain all of our available funds and future earnings, if any, for use in the operation and expansion of our business. Our loan agreement with Comerica Bank prohibits us from paying
cash dividends on our common stock and the terms of any future loan agreement we enter into or any debt securities we may issue are likely to contain similar restrictions on the payment of dividends. Subject to the foregoing, the payment of cash
dividends in the future, if any, will be at the discretion of our board of directors and will depend upon such factors as earnings levels, capital requirements, restrictions imposed by applicable law, our overall financial condition and any other
factors deemed relevant by our board of directors.

The following table sets forth our cash, cash equivalents and short-term investments, any cash held in escrow and our capitalization as of
March 31, 2013:



on an actual basis;



on a pro forma basis to reflect the filing of our amended and restated certificate of incorporation and the conversion of our shares of preferred stock
into an aggregate of 9,396,767 shares of common stock immediately prior to the consumation of this offering; and



on a pro forma as adjusted basis to further reflect the issuance and sale by us of shares of our common stock in this offering at an assumed
initial public offering price of $15.00 per share, which is the midpoint of the price range listed on the cover of this prospectus, after deducting the estimated underwriting discount and estimated offering expenses payable by us and the receipt by
us of the expected net proceeds of such sale.

You should read this information together with the sections
entitled Managements Discussion and Analysis of Financial Condition and Results of Operations and Selected Financial Data as well as our financial statements and the related notes, which appear elsewhere in this
prospectus.

A $1.00 increase (decrease) in the assumed initial public offering price of $15.00 per share would increase (decrease) each of cash, cash equivalents
and short-term investments, additional paid-in capital, total stockholders equity and total capitalization by approximately $4.7 million, assuming the number of shares we are offering, as set forth on the cover page of this prospectus, remains the
same, after deducting the estimated underwriting discount and estimated offering expenses payable by us. We may also increase or decrease the number of shares we are offering. An increase (decrease) of 1,000,000 shares in the number of shares we are
offering would increase (decrease) each of cash, cash equivalents and short-term investments, additional paid-in capital, total

stockholders equity and total capitalization by approximately $14.0 million and common stock by $5,000, assuming an initial public offering price of $15.00 per share, which is the midpoint of the
price range set forth on the cover page of this prospectus, and after deducting the estimated underwriting discount and estimated offering expenses payable by us. The pro forma as adjusted information is illustrative only, and we will adjust this
information based on the actual initial public offering price, number of shares offered and other terms of this offering determined at pricing.

The outstanding share information in the table above is based on 9,618,039 shares of our common stock outstanding as of March 31, 2013 (including convertible preferred stock on an as-converted basis), and
excludes the following:



1,441,252 shares of our common stock issuable upon the exercise of stock options outstanding at a weighted-average exercise price of $7.18 per share;



901,023 shares of our common stock (assuming the sale of 5,000,000 shares of our common stock in this offering) issuable upon the exercise of options
granted under our 2013 Equity Compensation Plan, or the 2013 Plan, which will become effective upon the consummation of this offering and will have an exercise price equal to the initial public offering price set forth on the cover page of this
prospectus;



up to 781,089 shares of our common stock reserved for future award under the 2013 Plan (assuming the sale of 5,000,000 shares of our common stock in
this offering);



96,360 shares of our common stock reserved for future issuance under our Employee Stock Purchase Plan which will become effective upon the consummation
of this offering; and



38,122 shares of our common stock issuable upon the exercise of common stock warrants and convertible preferred stock warrants outstanding at a
weighted-average exercise price of $5.66 per share.

If you invest in our common stock in this offering, your ownership interest will be immediately diluted to the extent of the difference
between the initial public offering price per share of our common stock and the pro forma as adjusted net tangible book value per share of our common stock immediately after this offering.

Our historical net tangible book value (deficit) is the amount of our total tangible assets less our total liabilities. Net historical
tangible book value (deficit) per share is our historical net tangible book value (deficit) divided by the number of shares of common stock outstanding as of March 31, 2013. Our net tangible book value (deficit) as of March 31, 2013 was
$16.4 million, or $74.23 per share.

Pro forma net tangible book value (deficit) gives effect to the conversion of our
convertible preferred stock into an aggregate of 9,396,767 shares of our common stock which will occur immediately prior to the consummation of this offering. Our pro forma net tangible book value (deficit) as of March 31, 2013 would have been
approximately $16.4 million, or $1.71 per share.

Pro forma as adjusted net book value is our pro forma net tangible book value
(deficit), after giving effect to the sale of shares of our common stock in this offering at an assumed initial public offering price of $15.00 per share, which is the midpoint of the price range listed on the cover of this prospectus, and
after deducting the estimated underwriting discount and estimated offering expenses payable by us. Our pro forma as adjusted net book value as of March 31, 2013 would have been approximately $84.7 million, or $5.79 per share. This amount
represents an immediate increase in pro forma as adjusted net tangible book value of $4.08 per share to our existing stockholders, and an immediate dilution of $9.21 per share to new investors participating in this offering. Dilution per share to
new investors is determined by subtracting pro forma as adjusted net tangible book value per share after this offering from the initial public offering price per share paid by new investors.

The following table illustrates this dilution on a per share basis:

Assumed initial public offering price per share

$

15.00

Historical net tangible book value (deficit) per share as of March 31, 2013

$

74.23

Pro forma decrease in net tangible book value per share attributable to the conversion of convertible preferred
stock

(72.52

)

Pro forma net tangible book value per share as of March 31, 2013

1.71

Pro forma increase in net tangible book value per share attributable to new investors

$

4.08

Pro forma as adjusted net tangible book value per share, after giving effect to this offering

5.79

Dilution of pro forma as adjusted net tangible book value per share to new investors

$

9.21

If the underwriters exercise their overallotment option in full, the pro forma as adjusted net tangible
book value per share after giving effect to this offering would be $6.19 per share, which amount represents an immediate increase in pro forma as adjusted net tangible book value of $4.48 per share of our common stock to existing stockholders and an
immediate dilution in pro forma as adjusted net tangible book value of $8.81 per share of our common stock to new investors purchasing shares of common stock in this offering. Each $1.00 increase (decrease) in the assumed initial public
offering price of $15.00 per share would increase (decrease) the pro forma net tangible book value, as adjusted to give effect to this offering, by $0.34 per share and the dilution to new investors by $0.66 per share, assuming the number of shares
offered by us, as set forth on the cover page of this prospectus, remains the same, after deducting the estimated underwriting discount and estimated offering expenses payable by us.

We may also increase or decrease the number of shares we are offering. An increase (decrease) of 1,000,000 shares in the number of
shares we are offering would increase (decrease) our pro forma as adjusted net tangible book value by approximately $14.0 million, or $0.89 per share, and decrease (increase) the pro forma dilution per share to investors in this offering by
$0.89 per share, assuming an initial public offering price of $15.00 per share, which is the midpoint of the price range set forth on the cover page of this prospectus, and after deducting the estimated underwriting discount and estimated
offering expenses payable by us. The pro forma

information discussed above is illustrative only and will change based on the actual initial public offering price, number of shares and other terms of this offering determined at pricing.

If any shares are issued upon exercise of outstanding options or warrants, you may experience further dilution. The number of
shares of our common stock reflected in the discussion and tables above is based on 9,618,039 shares of our common stock outstanding as of March 31, 2013 (including convertible preferred stock on an as-converted basis), and excludes the
following:



1,441,252 shares of our common stock issuable upon the exercise of stock options outstanding at a weighted-average exercise price of $7.18 per share;



901,023 shares of our common stock (assuming the sale of 5,000,000 shares of our common stock in this offering) issuable upon the exercise of options
granted under our 2013 Equity Compensation Plan, or the 2013 Plan, which will become effective upon the consummation of this offering and will have an exercise price equal to the initial public offering price set forth on the cover page of this
prospectus;



up to 781,089 shares of our common stock reserved for future award under the 2013 Plan (assuming the sale of 5,000,000 shares of our common stock in
this offering);



96,360 shares of our common stock reserved for future issuance under our Employee Stock Purchase Plan which will become effective upon the consummation
of this offering; and



38,122 shares of our common stock issuable upon the exercise of common stock warrants and convertible preferred stock warrants outstanding at a
weighted-average exercise price of $5.66 per share.

The following table summarizes, on the pro forma as
adjusted basis described above as of March 31, 2013, the number of shares of common stock purchased from us, the total consideration paid to us and the average price per share paid to us by our existing stockholders and by new investors
purchasing shares of common stock in this offering at the assumed initial public offering price of $15.00 per share, which is the midpoint of the price range listed on the cover page of this prospectus, before the deduction of the estimated
underwriting discount and estimated offering expenses payable by us. Investors purchasing shares of our common stock in this offering will pay an average price per share substantially higher than our existing stockholders paid.

Shares Purchased

Total Consideration

AveragePricePer
Share

Number

Percent

Amount

Percent

Existing stockholders before this offering

9,618,039

65.8

%

$

133,359,000

64.0

%

$

13.87

New investors participating in this offering

5,000,000

34.2

%

75,000,000

36.0

$

15.00

Total

14,618,039

100.0

%

$

208,359,000

100.0

%

$

14.25

A $1.00 increase (decrease) in the assumed initial public offering price of $15.00 per share would
increase (decrease) total consideration paid by new investors by $5.0 million and increase (decrease) the percent of total consideration paid by new investors by 1.5%, assuming the number of shares we are offering, as set forth on the cover page of
this prospectus, remains the same, after deducting underwriting discounts and commissions and estimated offering expenses payable by us. We may also increase or decrease the number of shares we are offering.

If the underwriters over-allotment option is exercised in full, the percentage of shares of our common stock held by existing
stockholders will be reduced to 62.6% of the total number of shares of our common stock outstanding after this offering, and the number of shares held by new investors will increase to 5,750,000 shares, or 37.4% of the total number of shares of our
common stock outstanding after this offering.

The number of shares purchased from us by existing stockholders is based on 9,618,039 shares
of our common stock outstanding as of March 31, 2013 (including convertible preferred stock on an as-converted basis), and excludes the following:



1,441,252 shares of our common stock issuable upon the exercise of stock options outstanding at a weighted-average exercise price of $7.18 per share;



901,023 shares of our common stock (assuming the sale of 5,000,000 shares of our common stock in this offering) issuable upon the exercise of options
granted under our 2013 Plan, which will become effective upon the consummation of this offering and will have an exercise price equal to the initial public offering price set forth on the cover page of this prospectus;



up to 781,089 shares of our common stock reserved for future award under the 2013 Plan (assuming the sale of 5,000,000 shares of our common stock in
this offering);



96,360 shares of our common stock reserved for future issuance under our Employee Stock Purchase Plan which will become effective upon the consummation
of this offering; and



38,122 shares of our common stock issuable upon the exercise of common stock warrants and convertible preferred stock warrants outstanding at a
weighted-average exercise price of $5.66 per share.

Certain of our existing stockholders, included
stockholders affiliated with certain of our directors, have indicated an interest in purchasing up to an aggregate of approximately $29.5 million in shares of our common stock in this offering at the initial public offering price. However, because
indications of interest are not binding agreements or commitments to purchase, the underwriters could determine to sell more, less or no shares to any of these potential investors and any of these potential investors could determine to purchase
more, less or no shares in this offering. The foregoing discussion and tables do not reflect any potential purchases by these potential investors.

We may choose to raise additional capital through the sale of equity or convertible debt securities due to market conditions or strategic considerations even if we believe we have sufficient funds for our
current or future operating plans. To the extent that any of these options or warrants are exercised, new options are issued under our equity incentive plans or we issue additional shares of common stock or other equity securities in the future,
there may be further dilution to new investors participating in this offering.

The following table summarizes our selected financial data for the periods and as of the dates indicated. Our selected statements of
operations data for each of the years in the periods ended December 31, 2012 and 2011, and our selected balance sheet data as of December 31, 2012, have been derived from our audited financial statements and related notes included
elsewhere in this prospectus. Our selected statements of operations data for the three months ended March 31, 2013 and 2012, and our selected balance sheet data as of March 31, 2013, have been derived from our unaudited financial
statements and related notes included elsewhere in this prospectus. Our interim unaudited financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America on the same basis as the
annual audited financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments, necessary to a fair statement of our financial position as of March 31, 2013 and our results of our
operations for the three months ended March 31, 2013 and 2012. The results for the three months ended March 31, 2013 are not necessarily indicative of results to be expected for the year ending December 31, 2013, any other interim
periods or any future period or year. Our selected financial data should be read together with the section entitled Managements Discussion and Analysis of Financial Condition and Results of Operations and with our financial
statements and their related notes, which are included elsewhere in this prospectus.

See Note 8 of our Notes to Financial Statements appearing elsewhere in this prospectus for an explanation of the method used to calculate the basic and net loss per
common share.

(2)

The calculations for the unaudited pro forma net loss per common share, basic and diluted, assume the conversion of all our outstanding shares of convertible preferred
stock into shares of our common stock, as if the conversion had occurred at the beginning of the period presented.

You should read the following discussion and analysis of our financial condition and results of operations together with the section entitled Selected Financial Data and our financial
statements and related notes included elsewhere in this prospectus. Some of the information contained in this discussion and analysis or set forth elsewhere in this prospectus, including information with respect to our plans and strategy for our
business and related financing, includes forward-looking statements that involve risks and uncertainties. See Cautionary Note Regarding Forward-Looking Statements. Our actual results may differ materially from those described below. You
should read the Risk Factors section of this prospectus for a discussion of important factors that could cause actual results to differ materially from the results described in or implied by the forward-looking statements contained in
the following discussion and analysis.

Overview

We are a biopharmaceutical company focused on the discovery and development of novel, first-in-class, actively controllable antithrombotic drug systems for acute and sub-acute cardiovascular indications.
We are pioneering the discovery and development of two-component drug systems consisting of a therapeutic aptamer and its specific active control agent. Our actively controllable product candidates have the potential to improve outcomes, enhance the
patient experience and reduce overall treatment costs.

We are not profitable and do not expect to be profitable in the
foreseeable future. We have incurred net losses in each year since our inception, including net losses of approximately $13.1 million and $19.2 million for 2012 and 2011, respectively. For the three months ended March 31, 2013, we incurred a
net loss of $3.3 million, and as of March 31, 2013, we had an accumulated deficit of approximately $113.8 million. We have devoted most of our financial resources to research and development, including our preclinical development
activities and clinical trials. We have not completed development of any product candidate and we have therefore not generated any revenues from product sales. As a result, we expect to continue to incur net losses and negative cash flows for the
foreseeable future. These net losses and negative cash flows have had, and will continue to have, an adverse effect on our stockholders equity and working capital. Our recurring losses from operations raise substantial doubt about our ability
to continue as a going concern, and as a result, our independent registered public accounting firm included an explanatory paragraph in its report on our financial statements as of and for the year ended December 31, 2012 with respect to this
uncertainty. Because of the numerous risks and uncertainties associated with pharmaceutical product development, we are unable to accurately predict the timing or amount of increased expenses or when, or if, we will be able to achieve or maintain
profitability.

Financial Operations Overview

Revenue

To date, we have not generated any
product revenue. Our ability to generate product revenue, which we do not expect will occur for several years, if ever, will depend heavily on the successful development and eventual commercialization of our lead product candidate, REG1.

Research and Development Expenses

Research and development expenses consist of the costs associated with our research and discovery activities, conducting preclinical studies and clinical trials, manufacturing development efforts and
activities related to regulatory filings. Our research and development expenses consist of:



employee salaries and related expenses, which include non stock-based compensation benefits for the personnel involved in our research and development
activities;



external research and development expenses incurred under agreements with third-party contract research organizations, or CROs, and clinical sites;



expenses incurred to manufacture clinical trial materials; and



license fees for and milestone payments related to in-licensed products and technologies.

We expense research and development costs as incurred. Conducting a significant amount of
research and development is central to our business model. Product candidates in late stages of clinical development generally have higher development costs than those in earlier stages of clinical development, primarily due to the increased size
and duration of late stage clinical trials.

For the years ended December 31, 2012 and 2011 and for the three months ended
March 31, 2013 and 2012, we incurred aggregate research and development expenses of approximately $4.5 million, $9.7 million, $1.1 million and $1.4 million, respectively, for REG1. We expect to incur increased expenses related to our
single, open-label, 13,200 subject Phase 3 trial of REG1, or the REGULATE-PCI trial, which we expect to commence in the second half of 2013. We will also incur increased research and development expenses as we advance our other product candidates
and expand our research and development programs.

We track external development expenses and direct personnel expenses on each
indication for our product candidates. Substantially all of our research and development expenses for REG1 have related to its initial indication, although we expect certain of the data obtained will support development of additional REG1
indications as well as the development of REG2. Overhead costs related to facilities, depreciation, employee benefits and bonuses, stock-based compensation, research and development management and research and development support services and
supplies are not allocated to specific product candidates or indications, because the development projects tend to vary from period to period and internal resources are utilized across and benefit multiple programs over any given period of time. The
following table is a summary of our research and development expenses for the years ended December 31, 2012 and 2011, the three months ended March 31, 2013 and 2012 and for the period from inception to March 31, 2013:

Years ended December 31,

Three months endedMarch 31,

Period from
Inception(December 19, 2001) toMarch 31, 2013

2012

2011

2013

2012

(in thousands)

REG1

$

4,530

$

9,651

$

1,111

$

1,412

$

62,547

REG3

419

1,827

122

113

5,710

REG2

356

384

110

85

4,197

Total research and development expense

$

5,306

$

11,862

$

1,343

$

1,609

$

72,454

The successful development of our clinical and preclinical product candidates is highly uncertain. At this
time, other than as discussed below, we cannot reasonably estimate the nature, timing or costs of the efforts that will be necessary to complete the remainder of the development of any of our product candidates or the period, if any, in which
material net cash inflows from those product candidates may commence. This is due to the numerous risks and uncertainties associated with developing drugs, including the uncertainty of:



the number of trials required for approval;



the number of sites included in the trials;



the number of countries included in the trials;



the number of subjects that participate in the trial;



the per subject trial costs;



the length of time required to enroll suitable subjects, achieve interim milestones and complete clinical trials;



the cost and timeliness of obtaining clinical trial supplies; and



the phase of development of the product candidate.

Development timelines, probability of success and development costs vary widely. As a result of the uncertainties discussed above, we anticipate that we will make determinations as to which product
candidates and indications to pursue and how much funding to direct to each product candidate and indication on an ongoing basis. Accordingly, we cannot currently estimate with any degree of certainty the amount of time or money that we will be
required to expend in the future on the research and development of our product candidates.

General and administrative expenses consist principally of salaries and related costs, including stock-based compensation expenses and
benefits, for all personnel. Other general and administrative expenses including all facility costs, and professional fees for legal, consulting, auditing and tax services. We anticipate that our general and administrative expenses will increase in
future periods to support increases in our research and development activities and as a result of increased headcount, expanded infrastructure, and increased legal, compliance, accounting and investor and public relations expenses associated with
being a public company.

Interest Income (Expense)

Interest income consists of interest earned on our cash and cash equivalents. We expect our interest income to increase following the
completion of this offering as we invest the net proceeds from this offering pending their use in our operations. Interest expense in 2011 related to interest paid on our loan with MidCap Financial SBIC, LP, or MidCap. Interest expense in 2012
related to interest paid on our MidCap loan and incurred on our convertible notes.

Critical Accounting Policies and Significant Judgments
and Estimates

Our managements discussion and analysis of financial condition and results of operations is based on
our consolidated financial statements, which have been prepared in accordance with U.S. generally accepted accounting principles, or GAAP. The preparation of our financial statements requires us to make estimates and judgments that affect the
reported amounts of assets, liabilities, revenue and expenses and related disclosure of contingent assets and liabilities. On an ongoing basis, we evaluate our estimates based on historical experience, known trends and events and various other
factors, which management believes to be reasonable under the circumstances, the results of which form the basis for judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may
differ from these estimates under different assumptions or conditions.

The notes to our audited financial statements, which
are included elsewhere in this prospectus, contain a summary of our significant accounting policies. We consider the following accounting policies critical to the understanding of the results of our operations.

Accrued Expenses

As part of the process of preparing our financial statements, we are required to estimate our accrued expenses. This process involves reviewing quotations and contracts, identifying services that have
been performed on our behalf and estimating the level of service performed and the associated cost incurred for the service when we have not yet been invoiced or otherwise notified of the actual cost. The majority of our service providers invoice us
monthly in arrears for services performed or when contractual milestones are met. We make estimates of our accrued expenses as of each balance sheet date in our financial statements based on facts and circumstances known to us at that time. We
periodically confirm the accuracy of our estimates with the service providers and make adjustments if necessary. The significant estimates in our accrued research and development expenses include fees paid to CROs in connection with research and
development activities for which we have not yet been invoiced.

We base our expenses related to CROs on our estimates of the
services received and efforts expended pursuant to quotes and contracts with CROs that conduct research and development on our behalf. The financial terms of these agreements are subject to negotiation, vary from contract to contract and may result
in uneven payment flows. There may be instances in which payments made to our vendors will exceed the level of services provided and result in a prepayment of the research and development expense. In accruing service fees, we estimate the time
period over which services will be performed and the level of effort to be expended in each period. If the actual timing of the performance of services or the level of effort varies from our estimate, we adjust the accrual accordingly. Although we
do not expect our estimates to be materially different from amounts actually incurred, our understanding of the status and timing of services performed relative to the actual status and timing of services performed may vary and could result in us
reporting amounts that are too high or too low in any particular period.

We record the fair value of stock options issued to employees and directors as of the grant date as compensation expenses. We recognize
compensation expenses over the requisite service period, which is the vesting period. For non-employees, we also record stock options at their fair value as of the grant date. We then periodically re-measure the awards to reflect the current fair
value at each reporting period until the non-employee completes the performance obligation or the date on which a performance commitment is reached. Compensation expenses are recognized over the related service period.

We calculate the fair value of stock-based compensation awards using the Black-Scholes option-pricing method. The Black-Scholes
option-pricing method requires the use of subjective assumptions, including stock price volatility, the expected life of stock options, risk free interest rate and the fair value of the underlying common stock on the date of grant. The assumptions
used in the Black-Scholes option-pricing method for the years ended December 31, 2012 and 2011 and for the three months ended March 31, 2013 and 2012 are set forth below:

Years endedDecember 31,

Three months endedMarch 31,

2012

2011

2013

2012

Expected dividend yield

0.00%

0.00%

0.00%

0.00%

Expected stock-price volatility

44.05%

45.82%

43.86%

45.32%

Risk-free interest rate

1.38%

1.50%

1.24%

1.61%

Expected term of options

6.25 years

6.25 years

6.25 years

6.25 years

Expected dividend yield. We base the expected dividend yield assumption on the fact that we
have never paid cash dividends and have no present intention to pay cash dividends on our common stock.

Expected
stock-price volatility. The expected stock-price volatility assumption is based on volatilities of a peer group of similar companies whose share prices are publicly available. The peer group was developed based on companies in the
biotechnology industry. In selecting the peer group, management considered publicly-traded biopharmaceutical companies with existing clinical stage anticoagulants or cardiovascular therapies. Management further considered the development stage of
the peer group companies. Approximately half of the peer group companies are development or clinical stage companies and the other half have a range of products at various phases of clinical trials, including one company that markets a product that
management considers directly competitive with our product candidates. Management also considered the financial leverage of the peer group companies. In general, management selected peer group companies that have no to low leverage levels. In
connection with its July 15, 2011 valuation, management determined to exclude one comparable company from its volatility analysis because it had extremely high leverage ratios and in connection with its December 31, 2012 valuation management
determined to exclude two comparable companies from its volatility analysis for the same reason.

Risk-free interest
rate. We base the risk-free interest rate assumption on observed interest rates appropriate for the expected term of the stock option grants.

Expected term of options. The expected term of options represents the period of time that options are expected to be outstanding. Because we do not have historic exercise behavior, we
determine the expected life assumption using the simplified method, which is an average of the contractual term of the option and its ordinary vesting period.

If we determine that other methods are more reasonable, or other methods for calculating these assumptions are prescribed by regulators, the fair value calculated for our stock options could change
significantly. Higher volatility and longer expected lives would result in an increase to stock-based compensation expense determined at the date of grant. Stock-based compensation expense affects our general and administrative expenses.

The following table presents the grant dates, number of underlying shares and related
exercise prices of stock options granted to employees and consultants since January 1, 2011, as well as the estimated fair value of the underlying common stock at each grant date:

Grant Date

Number ofSharesUnderlyingOption Grant

Exercise Priceper Share

Fair ValueEstimate perCommon Share

August 1, 2011

1,497

$

3.84

$

3.84

September 28, 2011 (1)

229,767

$

3.84

$

3.84

April 6, 2012

299

$

3.84

$

3.84

April 25, 2012

299

$

3.84

$

3.84

(1)

As discussed below, 228,270 of the options were subsequently cancelled and then regranted effective April 25, 2012.

The intrinsic value of our outstanding vested and unvested option grants as of March 31, 2013, assuming an initial public offering price
of $15.00 per share, which is the midpoint of the price range listed on the cover of this prospectus, and taking into account the applicable exercise price of such options, is set forth in the following table:

ExercisePrice

OptionsOutstanding

OptionsExercisable

IntrinsicValue perShare(1)

IntrinsicValue(Vested)

IntrinsicValue(Unvested)

$

1.67

73,770

73,770

$

13.33

$

983,354



$

2.00

299

299

$

13.00

$

3,887



$

3.34

41,616

41,616

$

11.66

$

485,243



$

3.84

229,467

105,010

$

11.16

$

1,171,912

$

1,388,940

$

4.51

538,244

441,105

$

10.49

$

4,627,191

$

1,018,988

$

9.69

598

598

$

5.31

$

3,175



$

10.86

120,479

120,479

$

4.14

$

498,783



$

11.69

138,083

137,815

$

3.31

$

456,168

$

887

$

12.53

298,093

298,093

$

2.47

$

736,290



(1)

Intrinsic value per share is calculated by subtracting the applicable exercise price from the assumed initial public offering price of $15.00 per share, which is the
midpoint of the price range listed on the cover of this prospectus.

Common Stock Fair Value

Due to the absence of an active market for our common stock, the fair value of our common stock for purposes of
determining the exercise price for stock option grants was determined by our board of directors, with the assistance and upon the recommendation of management, in good faith, based on a number of objective and subjective factors consistent with the
methodologies outlined in the American Institute of Certified Public Accountants Practice Aid, Valuation of Privately-Held-Company Equity Securities Issued as Compensation, including:



the prices at which we most recently sold our preferred stock and the rights, preferences and privileges of the preferred stock as compared to those of
our common stock, including the liquidation preferences of the preferred stock;



our results of operations, financial position and the status of our research and development efforts, including the status of clinical trials for REG1
and our specific regulatory status and interactions with regulatory authorities;



the likelihood of achieving a liquidity event for the holders of our common stock and stock options, such as an initial public offering, or IPO, given
prevailing market conditions, or a strategic merger or sale of our company;



the material risks related to our business;



achievement of enterprise milestones, including the results of clinical trials and our entry into or termination of collaboration and license
agreements;

the market performance of publicly traded companies in the life sciences and biotechnology sectors, and recently completed mergers and acquisitions of
companies comparable to us;



external market conditions affecting the life sciences and biotechnology industry sectors; and



a valuation prepared by an independent third-party consultant.

July 15, 2011 Valuation

An analysis of the enterprise value of our company and the fair market value of our common stock was conducted July 15, 2011. We utilized an option pricing method to value our common stock conducted
as of July 15, 2011 for purposes of establishing stock option exercise prices and for utilization in the Black-Scholes option-pricing method for calculating stock-based compensation expense as discussed below. The resulting implied per share value
of our common stock was $3.84 per share as of July 15, 2011. The option based model was employed to assess the value of common stock based on our capital structure, and this option based model considered the relative rights and preferences of
the various securities, including the seniority of the liquidation preferences for debt and preferred equity, and the potential for dilution caused by the conversion of the preferred equity. Our preferred stockholders have various rights that
give them greater control and influence over future liquidity, financing and other decisions relating to our company than the holders of our common stock. The option pricing methodology applied probabilities at each stage of development to assess
the likelihood of success at each stage, and a 10% discount for lack of marketability was applied.

The valuation was
determined using a discounted cash flow, or DCF, analysis, which establishes value for a company based on expected future economic benefits. The estimation of future cash flows was based on a financial forecast prepared by management. In applying
the DCF analysis, projected cash flows are discounted to present value using a discount rate that reflects investor-required rates of return for similar investments. The enterprise value was then allocated among the different classes of stock
using the Black-Scholes option-pricing method. The Black-Scholes option-pricing method treats common stock and preferred stock as call options on the enterprises value, with exercise prices based on the liquidation preference of the
preferred stock. Under this method, the common stock has value only if the funds available for distribution to stockholders exceed the value of the liquidation preference at the time of a liquidity event, assuming the enterprise has funds to
make a liquidation preference meaningful and collectible by the stockholders. The common stock is modeled as a call option that gives its owner the right, but not the obligation, to buy the underlying enterprise value at a predetermined or
exercise price. In the model, the exercise price is based on a comparison with the enterprise value rather than, as in the case of a standard call option, a comparison with a per-share stock price. Thus, common stock is considered to be a
call option with a claim on the enterprise at an exercise price equal to the remaining value immediately after the preferred stock is liquidated. This method considers the various terms of the stockholder agreements, including the level of
seniority among the securities, dividend policy, conversion ratios, and cash allocations, upon liquidation, of the enterprise as of the future liquidation date.

Stock Option Grants on August 1, 2011 and September 28, 2011

Our
board of directors granted stock options on August 1, 2011 and September 28, 2011, having an exercise price of $3.84 per share, which our board of directors determined to be equal to the fair value of our common stock on each date of
grant. The exercise price per share determined by our board of directors was supported by the July 15, 2011 valuation referenced above. The specific facts and circumstances considered by our board of directors for the July 15, 2011
valuation included the following:



on May 25, 2011, we sold 16,111,111 shares of our Series D Preferred Stock at a purchase price of $0.72 per share for aggregate gross
proceeds of $11.6 million and secured a $6.0 million loan from MidCap;



the regulatory status of our product candidates;



the general market conditions for private company financings for development stage companies, including strategic alignments; and

The resulting value, which represented the estimated fair value of our common stock, as of
August 1, 2011 and September 28, 2011, was $3.84 per share.

In addition to the objective and subjective factors listed above,
our board of directors also considered input from management and the valuation as of July 15, 2011 and determined there was no change in the fair value of our common stock between July 15, 2011 and September 28, 2011.

Stock Option Grants on April 6, 2012 and April 25, 2012

After a determination by our board of directors that our 2004 Equity Compensation Plan, as amended, or equity plan, contained inadequate
authorized shares for the September 28, 2011 stock option issuances, the board of directors cancelled the September 28, 2011 options and regranted the options after amending the equity plan. The equity plan was amended and options
regranted effective April 25, 2012 with the same exercise price, effective date, and vesting schedules as the original September 28, 2011 grants. This was accounted for as a modification on our financial statements and had no material
impact on the financial statements. Additional options were granted on April 6, 2012. The exercise price of both option grants was $3.84 per share, which our board of directors determined to be equal to the fair value of our common stock on
each date of grant. The exercise price per share determined by our board of directors was supported by an independent third party valuation as of July 15, 2011. In determining the exercise price for these grants, our board of directors
considered that there had been no change in the specific facts and circumstances considered by our board of directors in connection with the July 15, 2011 valuation.

The resulting value, which represented the estimated fair value of our common stock as of April 6, 2012, and April 25, 2012 was $3.84 per share.

December 31, 2012 Valuation

As of December 31, 2012, we utilized the probability weighted expected return method, or PWERM, to value our common stock for purposes of the Black-Scholes option-pricing method for calculating
stock-based compensation expense. In determining the value of our common stock, we relied also in part upon an independent third-party valuation performed as of December 31, 2012. The resulting implied per share value of our common stock
was $9.85 at December 31, 2012. We have not issued any stock options subsequent to April 25, 2012.

The
December 31, 2012 valuation of common stock was determined using the PWERM approach which incorporates the future enterprise value estimated under various potential future liquidity events and applies probabilities to each scenario. The
enterprise value for each scenario was estimated using a DCF analysis, which establishes value for a company based on expected future economic benefits. The estimation of future cash flows was based on a financial forecast prepared by
management. In applying the DCF method, projected cash flows are discounted to present value on the assumed date of the liquidity event using a discount rate that reflects investor-required rates of return for similar investments. The enterprise
value estimated for the future liquidity events is then allocated among the different classes of stock, probability adjusted and discounted to present value, resulting in a probability-weighted equity value of a company. For our valuation, we
considered the following future scenarios: an IPO at June 30, 2013, an IPO at December 31, 2013, a strategic merger or sale of our company by March 31, 2014 and failure or dissolution of our company with no value to our common
stockholders.

The weight attributed to each of these scenarios is set forth in the table below:

Scenario

Weight

IPO by June 30, 2013

50

%

IPO by December 31, 2013

30

%

Acquisition by March 31, 2014

10

%

Dissolution and liquidation

10

%

In determining the value of our common stock in the scenarios for an IPO, we assumed that the preferred
stock then outstanding would be converted into common stock. In allocating value to our common stock in the

merger or sale scenarios, we first allocated to our outstanding shares of preferred stock the greater of the liquidation preference of the preferred stock and the amount that would have been
payable had all such shares of preferred stock been converted to common stock immediately prior to such event, and then allocated any remaining value to our common stock. A 2.5% discount for lack of marketability was applied, and the various
rights of our preferred stockholders, including greater control and influence over future liquidity, financing and other decisions, were factored into the overall assessment. We believe that a lower marketability discount compared to that used in
the July 15, 2011 valuation was justified by several factors, including our belief that the results of our randomized, partially blinded, dose-ranging Phase 2b trial involving 640 subjects, or the RADAR trial, and our post-Phase 2b meetings with the
U.S. Food and Drug Administration and the European Medicines Agency, made our company more attractive to potential acquirers and investors, our understanding, based on input received from members of our board of directors, investors and investment
bankers, that market conditions had improved for initial public offerings by life science companies, and steps that we had taken to prepare our company for an IPO and in anticipation of the preparation and filing of the registration statement of
which this prospectus forms a part.

In connection with the issuance of shares of our Series E Preferred Stock on December 18,
2012, we used the fair value of our common stock as of December 31, 2012, calculated as described above, for the purpose of determining whether we were required to recognize a beneficial conversion feature with respect to those shares. Under GAAP,
we are required to recognize a beneficial conversion feature if the effective conversion price of shares of our Series E Preferred Stock was less than the fair value of our common stock on the date of issuance. Because the effective conversion price
of the Series E Preferred Stock issued on December 18, 2012 was greater than $9.85, we were not required to recognize a beneficial conversion feature with respect to those shares.

March 22, 2013 Valuation

In connection with the issuance of shares of our Series E Preferred Stock on March 22, 2013, we determined the fair value of our common stock as of that date for the purpose of determining whether we
were required to recognize a beneficial conversion feature with respect to those shares.

To determine the fair value of our
common stock on that date, we utilized the PWERM approach to value our common stock for purposes of the Black-Scholes option-pricing method. We also relied in part upon an independent third-party valuation performed as of December 31, 2012. The
resulting implied per share value of our common stock was $11.19 at March 22, 2013. Because the effective conversion price of the Series E Preferred Stock issued on that date was greater than $11.19, we were not required to recognize a
beneficial conversion feature with respect to those shares.

For our valuation, we considered the following future scenarios:
an IPO at June 30, 2013, an IPO at December 31, 2013, a strategic merger or sale of our company by March 31, 2014 and failure or dissolution of our company with no value to our common stockholders.

The weight attributed to each of these scenarios is set forth in the table below:

Scenario

Weight

IPO by June 30, 2013

80

%

IPO by December 31, 2013

10

%

Acquisition by March 31, 2014

0

%

Dissolution and liquidation

10

%

In determining the value of our common stock in the scenarios for an IPO, we assumed that the preferred
stock then outstanding would be converted into common stock. In allocating value to our common stock in the merger or sale scenarios, we first allocated to our outstanding shares of preferred stock the greater of the liquidation preference of the
preferred stock and the amount that would have been payable had all such shares of preferred stock been converted to common stock immediately prior to such event, and then allocated any remaining value to our common stock. A 2.5% discount for lack
of marketability was applied.

The increase in valuation between December 31, 2012 and March 22, 2013
resulted primarily from an increase in the overall IPO weighting from 80% to 90% and an increase in the weighting that an IPO would occur by June 30, 2013 from 50% to 80%. We believe that the increased weighting was justified by several factors
described below. In February 2013, we met with the FDA to discuss the proposed protocol and other aspects of our REGULATE-PCI trial. In that meeting, the FDA advised us that because of our extensive discussions with the FDA regarding our
REGULATE-PCI trial, including the trial design, the trial protocol, inclusion-exclusion criteria, trial population, endpoint definition, duration of follow-up, statistical analysis plan and interim analyses, we would obtain no additional benefit
from pursuing a Special Protocol Assessment, or SPA, for the trial. As a result, we determined not to seek an SPA from the FDA for the REGULATE-PCI trial and to proceed with the REGULATE-PCI trial as currently designed promptly following the
completion of this offering. If the FDA had objected to our trial design or the other matters described above, we would have been required to make substantial changes to the trial to satisfy any FDA objections which would have resulted in a delay in
the commencement of the trial. In addition, if the FDA had required significant revisions to the trial design, including imposing a requirement that the trial be blinded, the cost of conducting the trial would have increased by tens of millions of
dollars and the commencement of the trial would have been delayed by approximately one year. We also initiated the process of hiring CROs and academic research organizations, or AROs, including preparing bid defenses and scope of work, established a
Data Safety Monitoring Board, or DSMB, at Stanford University and began to identify individual members to serve on the DSMB, drafted the statistical analysis plan for our REGULATE-PCI trial and identified a vendor for distribution of clinical trial
materials, each of which we believe made our company more attractive to potential acquirers and investors.

Additionally, we
believe that the increased weighting was justified by several factors, including our engagement of underwriters, our submission of a confidential draft registration statement for this offering on March 1, 2013, the progress made in preparing
for an IPO, and the closing of $5.1 million in additional sales of our Series E Preferred Stock. In addition, we considered the investor feedback from our testing-the-waters meetings and that market conditions had improved for initial
public offerings by similarly situated life science companies.

April 24, 2013 Valuation

In connection with the issuance of shares of our Series E Preferred Stock on April 24, 2013, we determined the fair value of our
common stock as of that date for the purpose of determining whether we were required to recognize a beneficial conversion feature with respect to those shares.

To determine the fair value of our common stock on that date, we utilized the PWERM approach to value our common stock for purposes of the Black-Scholes option-pricing method. We also relied in part upon
an independent third-party valuation performed as of December 31, 2012. The resulting implied per share value of our common stock was $11.52 at April 24, 2013. Because the effective conversion price of the Series E Preferred Stock issued
on that date was greater than $11.52, we were not required to recognize a beneficial conversion feature with respect to those shares.

For our valuation, we considered the following future scenarios: an IPO at June 30, 2013, an IPO at December 31, 2013, a strategic merger or sale of our company by March 31, 2014 and
failure or dissolution of our company with no value to our common stockholders.

The weight attributed to each of these
scenarios is set forth in the table below:

Scenario

Weight

IPO by June 30, 2013

95

%

IPO by December 31, 2013

0

%

Acquisition by March 31, 2014

0

%

Dissolution and liquidation

5

%

In determining the value of our common stock in the scenarios for an IPO, we assumed that the preferred
stock then outstanding would be converted into common stock. In allocating value to our common stock in the merger or sale scenarios, we first allocated to our outstanding shares of preferred stock the greater of the

liquidation preference of the preferred stock and the amount that would have been payable had all such shares of preferred stock been converted to common stock immediately prior to such event,
and then allocated any remaining value to our common stock. A 2.5% discount for lack of marketability was applied.

The
increase in valuation between March 22, 2013 and April 24, 2013 resulted primarily from an increase in the overall IPO weighting from 90% to 95% and an increase in the weighting that an IPO would occur by June 30, 2013 from 80% to
95%. We believe that the increased weighting was justified by several factors, including the submission of an amended confidential draft registration statement for this offering and the progress made in preparing for an IPO, the closing of $5.1
million in additional sales of our Series E Preferred Stock, and further progress we made in preparing for the commencement of our REGULATE-PCI trial. In addition, we considered the investor feedback from our testing-the-waters meetings
and that market conditions had improved for initial public offerings by similarly situated life science companies.

There are
significant judgments and estimates inherent in the determination of these inputs to the valuations. These judgments and estimates include assumptions regarding our future performance, including the regulatory status of our product candidates; the
value of completing an IPO at different time points; the potential value of a strategic merger or sale at different time points; and the timing and probability of continuing to successfully progress our various product candidates toward
commercialization under differing operational scenarios, as well as determinations of the appropriate valuation methods. If different assumptions had been applied in the valuations, our stock-based compensation expense, net loss and net loss per
share and our beneficial conversion analysis would have been significantly different. While the assumptions used represent managements best estimates, these estimates involve inherent uncertainties and the application of managements
judgment. As a result, if revisions are made to the underlying assumptions and estimates, our stock-based compensation expense and beneficial conversion analyses could vary significantly from period to period.

Events Following April 24, 2013 Valuation

On April 29, 2013, we publicly filed the registration statement of which this prospectus is a part with the Commission. In May 2013, we submitted an application to list shares of our common stock on
the NASDAQ Global Market upon the consummation of this offering. Since April 24, 2013, we also have made additional progress in preparing for the commencement of the REGULATE-PCI trial. In addition to communications with regulatory authorities
regarding various aspects of the trial design, we have, among other things, added clinical operations and project management staff to our organization to support the trial, hired additional CROs and AROs to assist us in conducting the trial, engaged
members of our study steering committee including country coordinators, engaged the DSMB at Stanford University and obtained agreement to participate from all DSMB members, finalized the study protocol, statistical analysis plan and study
operational plans, hired a vendor and initialized electronic case report forms and study database, begun trial site selection in the U.S. and the E.U., begun the process of implementing contracts with investigational sites and investigators,
initiated the documentation process necessary to receive local regulatory authority and institutional review board approvals, ordered comparator study drug for the trial, designed the packaging kit for clinical trial materials and engaged a vendor
for distribution of clinical trial materials. Although the trial has not commenced, we have incurred substantial expenses in connection with these preparations and believe that these preparations have significantly benefited our company by
shortening the time that would otherwise have been required to commence the trial.

In May 2013, the pricing committee of our
board of directors determined the price range for this offering. As is typical in IPOs, the estimated price range for this offering was not derived using a formal determination of fair value of our common stock, but was determined based in part on
negotiations between us and our underwriters. Among the factors that were considered in setting the price range were: the positive results of our meeting with the FDA in February 2013 regarding the REGULATE-PCI trial; the continuing progress we have
made preparing for the commencement of our REGULATE-PCI trial; the general conditions of the securities markets and the recent trading prices of pre-commercial biotechnology companies such as our company; and consideration of the valuation ranges
seen in recent IPOs for pre-commercial biotechnology companies. Compared to our most recent valuation conducted as of April 24, 2013, the price range included on the cover page of this prospectus assumes that the IPO has occurred at an initial

public offering price within that range and that a public market for our common stock has been created, and therefore the price range excludes any marketability discount and attributes no
weighting to any other outcome for our company.

Results of Operations

Three Months Ended March 31, 2013 and 2012

The following table sets forth certain information concerning our results of operations for the periods shown:

Three Months EndedMarch
31,

2013

2012

Change

(unaudited,

in thousands)

Operating expenses:

Research and development . . . . .

$

(1,343

)

$

(1,609

)

$

266

General and administrative . . . . .

(1,833

)

(2,313

)

480

Total operating expenses . . . . . . . .

(3,176

)

(3,922

)

746

Interest income (expense): . . . . . . . . . . . .

Interest income

1

2

1

Interest expense . . . . . . . . . . . . .

(115

)

(152

)

37

Total other income (expense) . . . .

(114

)

(150

)

36

Net Loss

$

(3,290

)

$

(4,072

)

$

782

Research and Development Expenses

Research and development expenses decreased by $266,000, to $1.3 million for the three months ended March 31, 2013, from $1.6 million
for the three months ended March 31, 2012. The decrease resulted primarily from higher expenses during the 2012 period related to the manufacture of REG1 for use in our REGULATE-PCI trial. The REG1 active pharmaceutical ingredient has a shelf
life of approximately four years and is expected to be used in 2013 and 2014.

General and Administrative Expenses

General and administrative expenses decreased by $480,000, to $1.8 million for the three months ended March 31, 2013,
from $2.3 million for the three months ended March 31, 2012. The decrease was primarily due to the closure of office space in North Carolina in 2012, as well as increased legal fees in 2012 associated with business development and strategic
planning activities.

Interest Income (Expense)

Interest income decreased by $1,000 for the three months ended March 31, 2013, compared to the three months ended March 31,
2012.

Interest expense decreased by $37,000, to $115,000 for the three months ended March 31, 2013, from $152,000 for the
three months ended March 31, 2012. The decrease was primarily due to a reduction in the principal balance on the MidCap Financial loan.

The following table sets forth certain information concerning our results of operations for the periods shown:

Years EndedDecember 31,

2012

2011

Change

(in thousands)

Operating expenses:

Research and development

$

(5,306

)

$

(11,862

)

$

6,556

General and administrative

(6,857

)

(7,042

)

185

Total operating expenses

(12,163

)

(18,904

)

6,741

Interest income (expense):

Interest income

5

7

(2

)

Interest expense

(904

)

(301

)

(603

)

Total other income (expense)

(899

)

(294

)

(605

)

Net loss

$

(13,062

)

$

(19,198

)

$

6,136

Research and Development Expenses

Research and development expenses decreased by $6.6 million to $5.3 million for the year ended December 31, 2012, from $11.9 million
for year ended December 31, 2011. The decrease was primarily due to a decrease of $6.0 million in clinical and manufacturing expenses in 2012 as a result of the completion in 2011 of our RADAR trial, manufacturing and clinical expense in
connection with preparing for our REGULATE-PCI trial and manufacturing expenses in connection with REG3 preclinical studies. With the exception of employee salaries and related expenses, almost all research and development expense incurred in 2012
was dedicated to the manufacture of sufficient drug product to supply our REGULATE-PCI Phase 3 trial in 2013. As a result, the supplies inventory balance at December 31, 2012 was $4.6 million compared to $5.3 million in research and development
expense for the year ended December 31, 2012. As described below, we expect to incur significantly increased research and development expenses in connection with our REGULATE-PCI trial.

General and Administrative Expenses

General and administrative expenses decreased by $0.2 million, to $6.8 million for the year ended December 31, 2012, from $7.0 million for year ended December 31, 2011. The decrease in expense
was primarily due to lower bonus payments in 2012. As described above, we expect that general and administrative expenses will increase significantly as we transition to operating as a public company.

Interest Income (Expense)

Interest income decreased by $2,000, to $5,000 for the year ended December 31, 2012, from $7,000 for the year ended December 31, 2011, primarily as a result of lower investable cash balances.

Interest expense increased by $0.6 million, to $0.9 million for the year ended December 31, 2012, from $0.3 million
for year ended December 31, 2011. The increase was primarily due to interest payable on our $6.0 million loan from MidCap which we entered into in 2011 and on our $6.8 million in convertible notes issued in May 2012.

Liquidity and Capital Resources

Sources of Liquidity

To date, we have not generated any product
revenue. We have funded our operations to date through sales of our equity and debt securities, bank borrowings and government grants. As of March 31, 2013, we had $11.0 million in cash and cash equivalents.

From inception through March 31, 2013, we received net cash proceeds of $5.8 million from
the sale of our Series A Preferred Stock, $19.9 million from sales of our Series B Preferred Stock, $23.0 million from sales of our Series C Preferred Stock, $51.2 million from sales of our Series D Preferred Stock, $6.8 million from sales of
convertible notes and $20.2 million from sales of our Series E Preferred Stock.

Comerica Loan

In May 2013, we entered into a Loan and Security Agreement, or the Loan Agreement, with Comerica Bank, or Comerica. Pursuant to the terms
of the Loan Agreement, we were initially eligible to borrow $4.5 million in an initial tranche, or Tranche One. Upon Comericas receipt of evidence satisfactory to Comerica that (i) the 1,000 patient interim analysis in the REGULATE-PCI
study is successful and performed by April 30, 2014 and (ii) we complete this offering and receive net proceeds of at least $50 million prior to June 30, 2013, we will have the option, which is exercisable until the earlier of 30 days
after satisfaction of such conditions or May 30, 2014, to borrow an additional $4 million in the second tranche, or Tranche Two.

The Comerica loan bears interest at Comericas Prime Reference Rate (as defined in the Loan Agreement) subject to a floor of 30 day LIBOR plus 250 basis points plus 4.0%. The Comerica loan is
interest-only until September 1, 2014. We must repay the principal amount in nine approximately equal consecutive monthly installments commencing on September 1, 2014. The loan matures on May 10, 2015.

In connection with the funding of Tranche One, we issued to Comerica a warrant to purchase 156,250 shares of our Series E Preferred
Stock at a price of $0.72 per share, or the Warrant Price, subject to adjustment for stock splits, combinations, reclassifications or exchanges and certain dilutive issuances. If we exercise our right to borrow the additional $4 million in Tranche
Two, the warrant will become exercisable for an additional number of shares of our Series E Preferred Stock equal to 100,000 divided by the Warrant Price. Upon the consummation of this offering, the warrant will become exercisable for 9,356
shares of our common stock, 17,673 shares if we borrow the additional $4 million in Tranche Two, at an exercise price of $12.02 per share.

The proceeds of Tranche One were used to repay in full amounts outstanding under our loan and security agreement with MidCap Financial SBIC, LP which has been terminated.

Under the terms of the Credit Agreement, we granted Comerica a first priority security interest in substantially all of our assets other
than our intellectual property.

The Credit Agreement contains customary affirmative and negative covenants including
continuation of legal existence and good standing; provision of monthly internal and annual audited financial statements and other customary financial information, payment of taxes, continuation in force of insurance, maintenance of inventory and
registration of intellectual property; as well as prohibitions against dispositions of assets, changes in corporate structure, mergers and acquisitions, incurrence of indebtedness or liens, distributions and investments. The Credit Agreement does
not contain any ongoing financial covenants.

The Credit Agreement provides that upon the occurrence of and during a period of
default, interest on the loan will accrue at a penalty rate. Upon the occurrence and during the continuance of a default, Comerica may, at its election, make all obligations under the Credit Agreement immediately due and payable, cease advancing
money or extending credit, exercise its right of setoff, foreclose on our assets, dispose of collateral at a public or private sale, and exercise any other remedies available to a secured creditor at law or in equity.

Under the terms of the Credit Agreement, events of default include failure to pay principal or interest when due; failure to adhere to any
of the affirmative or negative covenants; a material adverse change; we become insolvent; a material portion of our assets are attached or seized; we default or fail to perform in an agreement with a third party in which third party to accelerate
indebtedness in amount exceeding $250,000; or a judgment in excess of $250,000 not otherwise covered by insurance is rendered against us and remains unsatisfied for ten days.

Our net cash flow from operating, investing and financing activities for the periods below were as follows:

Three Months
EndedMarch 31,

Year EndedDecember 31,

2013

2012

2012

2011

(unaudited)

(in thousands)

Net cash provided by (used in):

Operating activities

$

(3,145

)

$

(4,169

)

$

(14,721

)

$

(21,742

)

Investing activities

(105

)

(158

)

(357

)

(189

)

Financing activities

(679

)

(1

)

20,607

17,486

Net increase (decrease) in cash and cash equivalents

$

(3,929

)

$

(4,328

)

$

5,529

$

(4,445

)

Operating Activities

Net cash used in operating activities was $3.1 million for the three months ended March 31, 2013 and $4.2 million for the three months ended March 31, 2012. Net cash used in operating activities for the
three months ended March 31, 2013 principally resulted from our net loss of $3.3 million and a higher level of prepaid expenses and other assets, partially offset by increases in accounts payable and accrued expenses. Net cash used in operating
activities for the three months ended March 31, 2012 principally resulted from our net loss of $4.1 million and a higher level of supplies inventory, partially offset by a decrease in prepaid expenses and other assets.

Net cash used in operating activities was $14.7 million for the year ended December 31, 2012 and $21.7 million for the year
ended December 31, 2011. Net cash used in operating activities for the year ended December 31, 2012 principally resulted from our net loss of $13.1 million and a higher level of inventory. Net cash used in operating activities for the
year ended December 31, 2011 principally resulted from our net loss of $19.2 million and a decrease in accounts payable.

Investing Activities

Net cash used in investing activities was $105,000 for the three months ended March 31, 2013 and $158,000 for the three months ended March 31, 2012. Net cash used in investing activities for the three
months ended March 31, 2013 principally resulted from expenses incurred in connection with the transfer of certain intellectual property rights pursuant to the terms of our Series E financing. Net cash used in investing activities for the three
months ended March 31, 2012 principally resulted from the expansion and defense of our intellectual property rights.

Net
cash used in investing activities was $0.4 million for the year ended December 31, 2012 and $0.2 million for the year ended December 31, 2011. Net cash used in investing activities for the years ended December 31, 2012 and
December 31, 2011 principally resulted from efforts to obtain and maintain intellectual property rights.

Financing
Activities

Net cash used in financing activities was $679,000 for the three months ended March 31, 2013 and $1,000
for the three months ended March 31, 2012. Net cash used in financing activities for the three months ended March 31, 2013 principally resulted from payments related to notes payable and stock issuance cost related to the Series E
financing.

Net cash provided by financing activities was $20.6 million for the year ended December 31, 2012 and $17.5
million for the year ended December 31, 2011. Net cash provided by financing activities for the year ended December 31, 2012 resulted primarily from $15.0 million in net cash proceeds from the sale of Series E Preferred Stock on
December 18, 2012 and $6.8 million in proceeds from sales of convertible notes, which subsequently converted into shares of Series E Preferred Stock together with accrued interest thereon. Net cash provided by financing activities for the year
ended December 31, 2011 principally resulted from the receipt of $11.6 million

in proceeds from the sale of additional shares of our Series D Preferred Stock in May 2011 and $6.0 million in proceeds of the MidCap loan.

Funding Requirements

We have not completed development of any of our product candidates. We expect to continue to incur significant expenses and increasing operating losses for at least the next several years. We anticipate
that our expenses will increase substantially as we:



initiate and conduct our REGULATE-PCI trial;



continue the research and development activities for our other product candidates;

establish a sales, marketing and distribution infrastructure if we do not secure a strategic partner to commercialize products for which we may obtain
regulatory approval;



increase manufacturing capabilities in preparation for commercial launch of any such products; and



add operational, financial and management information systems and personnel, including personnel to support our product development, planned
commercialization efforts and our operation as a public company.

We expect that the net proceeds from this
offering, together with our existing cash and cash equivalents, and anticipated interest income, will enable us to fund our operating expenses and capital expenditure requirements through the interim analysis at 50% enrollment in our REGULATE-PCI
trial, which we expect to occur by the end of 2014. Our forecast of the period of time through which our financial resources will be adequate to support our operations is a forward-looking statement and involves risks and uncertainties, and actual
results could vary as a result of a number of factors, including the factors discussed in the section entitled Risk Factors and elsewhere in this prospectus. We have based this estimate on assumptions that may prove to be wrong, and we
could utilize our available capital resources sooner than we currently expect.

Our future funding requirements, both near and
long-term, will depend on many factors, including, but not limited to:



the initiation, progress, timing, costs and results of preclinical studies and clinical trials for our product candidates and potential product
candidates, including our REGULATEPCI trial, and the continued development of our other product candidates;



the number and characteristics of product candidates that we pursue;



the terms and timing of any future collaboration, licensing or other arrangements that we may establish;

the cost and timing of completing commercial-scale outsourced manufacturing activities;



market acceptance of any product candidates for which we may receive regulatory approval;



the cost of establishing sales, marketing and distribution capabilities for any product candidates for which we may receive regulatory approval; and



the extent to which we acquire, license or invest in businesses, products or technologies.

Until we can generate a sufficient amount of revenue from our product candidates, if ever, we expect to finance future cash needs through
public or private equity offerings, debt financings or corporate collaborations

and licensing arrangements. Additional funds may not be available when we need them on terms that are acceptable to us, or at all. If adequate funds are not available, we may be required to
delay, reduce the scope of or eliminate one or more of our research or development programs or our commercialization efforts. To the extent that we raise additional funds by issuing equity securities, our stockholders may experience additional
dilution, and debt financing, if available, may involve restrictive covenants. To the extent that we raise additional funds through collaborations and licensing arrangements, it may be necessary to relinquish some rights to our technologies or our
product candidates or grant licenses on terms that may not be favorable to us. We may seek to access the public or private capital markets whenever conditions are favorable, even if we do not have an immediate need for additional capital at that
time.

We do not expect REG1 to be commercially available before 2017, if at all. The expected net proceeds of this offering
will not be sufficient for us to complete the REGULATE-PCI trial and we will need to raise substantial additional capital to complete the development and commercialization of REG1. We also will need to raise substantial additional capital to
complete the development and commercialization of REG1 for additional indications and for our other product candidates. Because successful development of our product candidates is uncertain, we are unable to estimate the actual funds required to
complete research and development and commercialize our products under development.

Future Contractual Obligations and Commitments

The following table reflects a summary of our estimates of future contractual obligations as of March 31, 2013. The
information in the table reflects future unconditional payments and is based on the terms of the relevant agreements, appropriate classification of items under U.S. GAAP as currently in effect and certain assumptions, such as the interest rate on
our variable debt that was in effect as of March 31, 2013. Future events could cause actual payments to differ from these amounts.

1-3 Years

Principal(1)

$

3,857,143

Interest(2)

$

316,045

Fees

$

180,000

Total

$

4,353,188

(1)

In May 2011, we obtained a $6.0 million loan from MidCap for working capital and general business purposes. The loan bears interest at the one-month LIBOR rate, subject
to a floor of 2.0%, plus 8.0% and matures on August 25, 2014. Subsequent to March 31, 2013, the MidCap loan was repaid with the proceeds of the loan from Comerica. See Liquidity and Capital ResourcesComerica Loan.

(2)

Estimated interest expense based on a variable rate of LIBOR plus 8%.

As described in BusinessLicense Agreements, upon the commencement of our REGULATE-PCI trial, we will be obligated to make milestone payments of $500,000 to Duke University, or Duke, and
$1.0 million to Archemix Corporation, or Archemix. In addition, upon the filing of a new drug application, we are obligated to make additional milestone payments to Duke, Archemix and Nektar Therapeutics AL, Corporation. Given the uncertainty of the
drug development process, we cannot be certain when, if ever, we will be required to make these milestone payments.

As of
March 31, 2013, we did not have lease agreements in effect for our laboratory facility in North Carolina and our office in New Jersey and were leasing these facilities on a month-to-month basis. On May 1, 2013, we entered into a three-year
lease for additional administrative office space in North Carolina. Annual rent under this lease is $38,940 for the first year, $39,917 for the second year and $40,911 for the third year. We have a lease for an additional office in North Carolina,
which expires in June 2013. The monthly rent payments under this lease are $1,835. See BusinessProperties.

We enter into contracts in the normal course of business with clinical research organizations for clinical trials and clinical supply
manufacturing and with vendors for preclinical research studies, research supplies and other services and products for operating purposes. These contracts generally provide for termination on notice,

and therefore we believe that our non-cancelable obligations under these agreements are not material. In April 2013 the Company has entered into certain cancelable agreements with academic
research organizations and clinical research organizations in preparation for the commencement of the REGULATE-PCI trial and made a prepayment of $2.7 million in connection therewith.

Tax Loss Carryforwards

At December 31, 2012, we evaluated and
assessed the expected near-term utilization of net operating loss carryforwards, book and taxable income trends, available tax strategies, and the overall deferred tax position and believes that it is more likely than not that the benefit related to
the deferred tax assets will not be realized and has thus established the valuation allowance required as of December 31, 2012. If actual results differ from the assumptions made in our evaluation, we may record a change in the valuation
allowance through income tax expense in the period such determination is made. We believe that the judgments and estimates are reasonable; however, actual results could differ. The Companys effective tax rate is zero due to continued taxable
losses, which generate deferred tax assets which are offset in their entirety by related valuation allowances, due to the uncertainty in realizing these tax benefits. As such the Company does not record quarterly accruals for corporate taxes.
Deferred income tax assets and liabilities are calculated and reported at year end.

Off-Balance Sheet Arrangements

Since inception, we have not engaged in any off-balance sheet activities as defined in Item 303(a)(4) of Regulation S-K.

Recent Accounting Pronouncements

Section 107 of the Jumpstart our Business Startups Act of 2012, or the JOBS Act, provides that an emerging growth company can take advantage of the extended transition period provided in
Section 7(a)(2)(B) of the Securities Act of 1933, as amended, for complying with new or revised accounting standards. In other words, an emerging growth company can delay the adoption of certain accounting standards until those
standards would otherwise apply to private companies. However, we are choosing to opt out of such extended transition period, and as a result, we will comply with new or revised accounting standards on the relevant dates on which
adoption of such standards is required for non-emerging growth companies. Section 107 of the JOBS Act provides that our decision to opt out of the extended transition period for complying with new or revised accounting standards is irrevocable.

In December 2011, the Financial Accounting Standards Board issued Accounting Standards Update, or the ASU,
No. 201111, Balance Sheet (Topic 210). This update provides enhanced disclosure requirements regarding the nature of an entitys right of offset related to arrangements associated with its financial instruments and
derivative instruments. The new guidance requires the disclosure of the gross amounts subject to rights of set-off, the amounts offset in accordance with the accounting standards followed, and the related net exposure. This pronouncement is
effective for financial reporting period beginning on or after January 1, 2013 and full retrospective application is required. We do not expect that the adoption of this ASU will have any material impact on our consolidated financial
statements.

Qualitative and Quantitative Disclosures about Market Risk

Our exposure to market risk is limited to our cash, cash equivalents and marketable securities, all of which have maturities of one year
or less. The goals of our investment strategy are preservation of capital, fulfillment of liquidity needs and fiduciary control of cash and investments. We also seek to maximize income from our investments without assuming significant risk. To
achieve our goals, we maintain a portfolio of cash equivalents and investments in a variety of securities that management believes to be of high credit quality. The securities in our investment portfolio are not leveraged, are classified as
available for sale and are, due to their short-term nature, subject to minimal interest rate risk. We currently do not hedge interest rate exposure. Because of the short-term maturities of our investments, we do not believe that an increase in
market rates would have a material negative impact on the value of our investment portfolio.

We are a
biopharmaceutical company focused on the discovery and development of novel, first-in-class, actively controllable antithrombotic drug systems for acute and sub-acute cardiovascular indications. We are pioneering the discovery and development of
two-component drug systems consisting of a therapeutic aptamer and its specific active control agent. Our actively controllable product candidates have the potential to improve outcomes, enhance the patient experience and reduce overall treatment
costs.

Each of our product candidates consists of a two-component system: an antithrombotic aptamer and its specific active
control agent. The aptamer is administered first and achieves its antithrombotic effect within minutes. When the antithrombotic effect of the aptamer is no longer needed, the control agent is administered to rapidly and precisely reduce or eliminate
it. The level of reduction is determined by the amount of control agent given compared to the aptamer dose. By contrast, the therapeutic effect of existing antithrombotic drugs is not rapidly and precisely controllable and persists until the drug is
metabolized by the patient, a process which varies from patient to patient and can take several hours or more.

Our lead
product candidate, REG1, consists of pegnivacogin, a highly potent and selective anticoagulant, and anivamersen, its specific active control agent. We are developing REG1 as an anticoagulant for use in patients with a wide variety of cardiovascular
conditions undergoing percutaneous coronary intervention, or PCI, a hospital-based procedure used to mechanically open or widen obstructed coronary arteries. Interventional cardiologists performing PCIs must consider the risk of major bleeding
events in determining the level of anticoagulation administered to patients to prevent ischemic events, including death, stroke, myocardial infarction, or MI, or the need for revascularization of the artery. Because the anticoagulant effect of
existing drugs persists long after administration, intervention cardiologists are forced to make a compromising medical decision because they lack the means to simultaneously reduce the risks of ischemic and major bleeding events. In 2005, we filed
an investigational new drug application, or IND, for the use of REG1 in this initial indication.

We believe that REG1 has the
potential to become the standard of care for anticoagulation therapy for patients undergoing PCI and other cardiovascular procedures because it gives the physician precise, on-demand control over anticoagulation levels. REG1 is the first and only
anticoagulant to demonstrate a reduction in both ischemic and major bleeding events in a clinical trial for PCI. In our clinical trials, REG1 demonstrated a rapid and predictable anticoagulant effect that was precisely modulated or completely
reversible in real time. In our randomized, partially blinded, dose-ranging Phase 2b trial involving 640 subjects, or the RADAR trial, when compared to standard of care heparin, REG1 demonstrated both a rapid and predictable anticoagulant effect and
ability to precisely modulate or eliminate that effect in real time. REG1 also demonstrated the following important clinical and pharmacoeconomic benefits:



an approximate 66.0% reduction in ischemic events;



a reduction of up to 60.0% in major bleeding events;



a substantial reduction in time from catheterization to catheter sheath removal from a median of 3.8 hours to a median of one hour;



a substantial reduction in time of completion of the PCI procedure to catheter sheath removal from a median of three hours to a median of 24 minutes;
and



a substantial reduction in the time patients were required to remain still following catheter sheath removal from a median of 5.7 hours to a median of
2.8 hours.

Based on these clinical results and after discussion with the U.S. Food and Drug Administration,
or FDA, and the European Medicines Agency, or EMA, in the second half of 2013, we intend to initiate a single, open-label, 13,200 subject Phase 3 trial of REG1, or the REGULATE-PCI trial, in patients undergoing PCI procedures other than for the
treatment of ST elevation myocardial infarctions. REGULATE-PCI, if successful, will serve as the basis for product registration applications worldwide. We believe that REG1 has potential use in other PCI

and interventional cardiovascular procedures, such as open heart surgery, or OHS, PCI as a treatment for ST segment elevation myocardial infarction as well as transcatheter aortic valve
replacement or implantation, or TAVI.

Using our proprietary technology platform, we are developing a portfolio of additional
clinical candidates in acute and sub-acute cardiovascular and other indications. REG3 is a preclinical stage antiplatelet therapy, consisting of a glycoprotein VI, or GPVI, inhibitor being evaluated in diabetic vasculopathy and other inflammatory
diseases. The specific active control agent component of REG3 is designed to permit modulation or elimination, if necessary, of the GPVI inhibition, if necessary, to optimize dosing and minimize unwanted side effects that might result from GPVI
inhibition. We plan to initiate a Phase 1 study of REG3 in 2014. We intend to file an IND for REG3 upon completion of our remaining pre-IND preclinical and chemistry, manufacturing and controls work. REG2 is an early clinical stage program
evaluating an extended release formulation of pegnivacogin intended to provide a controllable level of anticoagulation for up to two weeks for venous antithrombotic applications such as venous thromboembolism, or VTE, prophylaxis. In REG2,
anivamersen would be used as an active control agent if needed. We have completed a single escalating dose Phase 1 clinical trial of REG2 and plan to conduct additional clinical testing in the future. We intend to file an IND for REG2 upon
finalization of the protocol for the next clinical trial in the REG2 development program and completion of the manufacturing of the drug material for the trial. Additionally, we are evaluating potential product candidates against the receptor
CLEC-2, an antiplatelet target.

The following table lists our current product candidates and discovery programs and their
respective stages of development:

Our product candidates and proprietary technology platform are protected by a patent estate of 30
issued or allowed patents, including 14 in the United States, covering our composition of matter and methods of use for our product candidates as well as our fundamental controllable aptamer technology. We maintain worldwide commercialization rights
to all of our product candidates except in Armenia, Azerbaijan, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Moldova, Russia, Tajikistan, Turkmenistan, Ukraine and Uzbekistan, or the Covered Territory.

PCI Overview

PCIs are
hospital-based procedures used to mechanically open or widen obstructed coronary arteries. To treat this condition, a deflated balloon or other device on a catheter is inserted into an artery through an arterial sheath in the groin or wrist and
advanced to the site of a blockage. Normalized blood flow is restored by opening or widening the artery. A stent is often placed at the site of blockage to permanently maintain blood flow.

non-ST elevation myocardial infarction, or N-STEMI, which is an MI without electrocardiogram, or ECG, evidence of cell death but where chemical enzyme
analysis shows muscle damage has occurred or is occurring; and



ST elevation myocardial infarction, or STEMI, which is an acute MI with ECG evidence of cell death and abnormally high levels of chemical
enzymes.

Patients undergoing PCI as an elective procedure include patients with:



chest pain or discomfort that usually occurs with activity or stress, or stable angina, which is due to a coronary arterial blockage;



a significant change or worsening of coronary arterial blood flow on a stress test or echocardiogram; and



previous heart damage with a known coronary arterial blockage who return for additional treatment.

PCI procedures involve significant medical risks. Blood clots may exist at the blockage or may result from arterial damage at the point of
catheter insertion or from the presence of the catheter or other foreign materials in the vasculature. If blood clotting is not eliminated or controlled effectively, ischemic events, including death, stroke, MI or the need for revascularization of
the artery, may occur. Because of this risk, powerful anticoagulant drugs are administered prior to and throughout the PCI procedure. However, anticoagulants create a significant risk of major bleeding events, including bleeding into the heart, the
brain or other organs, massive internal bleeding that requires a significant transfusion of blood and blood products, and uncontrolled bleeding at the access site. These major bleeding events can result in the need for emergency surgery and increase
the risk of MI, stroke, other life-threatening complications and death.

Because the therapeutic effect of most existing
anticoagulants persists until they are metabolized by the patient, the risk of major bleeding events remains long after the procedure is completed, even when the anticoagulant administration is stopped at the end of the PCI. As a result, patients
must wait up to six hours post-procedure before the arterial sheath can be safely removed, increasing patient discomfort and requiring extended monitoring and potential intervention by medical staff. In certain circumstances, a vascular closure
device, or VCD, may be used to block or control bleeding at the access site to reduce this waiting time. However, it is not always possible to use a VCD and a VCD may not significantly reduce the risk of a major bleeding event. In addition, the use
of a VCD adds significant cost to the procedure and may cause increased risk of vascular complications. As a result, the use of VCDs varies significantly from physician to physician and from hospital to hospital. If a VCD is not utilized, direct
compression at the access site by medical staff for up to 30 minutes is typically applied followed by application of a sandbag or other mechanical compression throughout the total wait time to prevent bleeding.

Interventional cardiologists performing a PCI are forced to make a compromising medical decision because they lack the means to
simultaneously reduce the risk of ischemic and major bleeding events. We believe that an antithrombotic treatment that can reduce both risks would create a new standard of care.

PCI Market

The PCI market is a large and growing market. According to the
American Heart Association, or the AHA, approximately 950,000 PCIs were performed in the United States in 2010. Based on information obtained from publicly available PCI procedure registries, we estimate that in 2010 approximately 1.1 million
PCIs were performed in Europe and at least 1.0 million in the rest of the world.

We expect that the global market for
PCIs will continue to grow while the market for PCIs in the United States and Europe will be relatively stable. Based on historical statistics published by the AHA, we believe that the growth in the number of PCIs performed in the United States will
correlate to the growth of the population over age 45, which the U.S. Census Bureau estimates will increase at a rate of approximately 1.2% annually for the next decade. PCI growth in emerging countries is expected to be much greater. The National
Center for Cardiovascular Diseases China reported that the number of PCIs performed in the Peoples Republic of China increased approximately 26% annually from 2005 to 2009 while the National Intervention Council estimated in 2010 that PCI
procedures in India would grow at approximately 25% annually. Based on 2008 statistics provided

by the Brazilian Public Health System we estimated a projected annual growth rate of approximately 9% in PCI procedures in Brazil. Based on similar information obtained from other countries, we
believe that similar increases in the number of PCI procedures are occurring throughout the developing world. This expected worldwide growth in PCI procedures is due to an expected increase in cardiovascular disease and such factors as an aging
population, increasing clinical adoption of PCI procedures and increasing PCI survival rates. Based upon the estimated cost per procedure of branded anticoagulants, we believe that this represents a greater than $3.0 billion annual market
opportunity for anticoagulants used in PCI procedures.

We intend to seek initial regulatory approval for the use of REG1 in
all PCI procedures other than in the treatment of STEMI. Based on 2010 statistics published by the Grace Registry and the Health Care Utilization Report 2010, we believe that approximately 2.3 million PCI procedures were performed worldwide in
2010 in this segment of the market. We anticipate that this segment of the market will grow faster than the overall PCI market as a result of an ongoing clinical shift toward less invasive cardiovascular procedures.

Current PCI Anticoagulants and Their Limitations

Anticoagulants are administered throughout a PCI procedure to reduce the chances of unwanted blood clots forming due to arterial damage at the point of catheter insertion or to the presence of the
catheter or other foreign materials in the vasculature. The anticoagulants most commonly used in PCI procedures are heparin and bivalirudin.

Heparin

Discovered in 1916, heparin is derived from the entrails of
pigs and cows. It is a non-specific, indirect inhibitor of thrombin and blood coagulation Factor Xa, or FXa. There are two forms of heparin: unfractionated heparin, or UFH, and low molecular weight heparin, or LMWH. LMWH is primarily used as an
antithrombotic treatment outside of the acute care setting and is used on a limited basis in PCI. When we refer to heparin, we mean UFH unless otherwise indicated. In PCI, heparin is first administered by IV bolus injection followed by a continuous
IV infusion during the procedure. Heparin has a number of shortcomings including:



Limited effectiveness. As an indirect thrombin inhibitor, heparin is ineffective on clots that have already formed or are in the process
of forming.



Major bleeding risk. Heparin requires 20 to 30 minutes to reach its peak anticoagulant effect; consequently physicians may exceed the
minimum effective dose to access a compromised artery faster. As a result, patients are exposed to a supratherapeutic level of anticoagulation well after the procedure is completed as the anticoagulant effect of heparin persists at significant
levels for up to six hours and the typical PCI procedure only requires approximately 30 to 60 minutes to complete. Female patients as well as patients who are elderly, frail or have kidney disease are particularly at risk for major bleeding events.
Also, physicians often use intravenous glycoprotein platelet, or GPIIb/IIIa, inhibitors along with heparin in patients with a high thrombus risk. Recent clinical trials have shown that bleeding risk increases when heparin is used in combination with
GPIIb/IIIa inhibitors.



Risk of immunological reaction. Patients receiving heparin can develop heparin-induced thrombocytopenia and thrombosis, or HIT/HITTS, a
dangerous and life-threatening immunological reaction that can result in amputation or death. A 2005 article in Thrombosis reported HIT/HITTS rates of up to 2.7% in all heparin patients.



Unpredictable pharmacokinetics. Heparin dosing is imprecise because its dose-response relationship is non-linear and it is metabolized at
varying rates from patient to patient. In addition, some patients are heparin-resistant. As a result, a patients unpredictable response to heparin requires close and continuous monitoring of anticoagulation levels.



No specific active control. Protamine, a drug that reverses the anticoagulant effect of heparin, is rarely used in PCI due to its
unpredictable effect and its adverse event profile, which includes allergic reactions, pulmonary hypertension and cross-reactivity with certain types of insulin. As a result, its use is generally limited to OHS, where the high level of heparin used
makes a reversal agent medically necessary despite

protamines shortcomings. If a physician needs to modulate heparins anticoagulant effect in a PCI procedure, an extensive transfusion of blood and blood products is the most commonly
used method. Additionally, if mechanical complications, such as the inadvertent perforation of an artery occur, extensive intervention including possible emergency surgery is required.



Quality and purity concerns. A substantial portion of the world supply of heparin comes from outside of the United States and the
European Union. In the recent past, contaminated heparin has been responsible for a number of deaths and other complications. In addition, variations in product potency are not uncommon.

Bivalirudin

Bivalirudin is a direct thrombin inhibitor administered by IV bolus injection followed by continuous IV infusion during the PCI procedure. In clinical studies, patients metabolized bivalirudin at a faster
rate than heparin. Although bivalirudin has demonstrated a lower rate of major bleeding events compared to heparin in clinical studies, it has a number of shortcomings:



Ischemic risk. In clinical trials, patients receiving bivalirudin had a numerically higher rate of ischemic events,
including MIs and stent clotting, than patients receiving heparin. As a result, physicians typically use heparin when treating unstable patients and patients at a higher risk of having an ischemic event.



Bleeding risk. Although bivalirudin is metabolized more quickly than heparin, its anticoagulant effect persists at
significant levels for up to four hours. As a result, patients are exposed to the risk of a major bleeding event for an extended period. Use of GPIIb/IIIa inhibitors with bivalirudin further exacerbates this risk.



No reversal agent.Because there is no reversal agent for bivalirudin, an extensive transfusion of blood and blood products
is the only means to modulate its anticoagulant effect. Due to its mechanism of action, emergency surgical intervention is more likely with bivalirudin than heparin in the event of mechanical complications such as the inadvertent perforation of an
artery.



Unpredictable dosing. Because bivalirudin is metabolized by the kidneys, dose adjustments are necessary for patients with
renal insufficiency. While standard coagulation tests can be performed, the results do not accurately indicate quantitative bivalirudin levels and therefore cannot be used to precisely make dose adjustments. In addition, because the amount of
bivalirudin necessary for the treatment of a specific patient depends both on the patients weight and the length of the PCI procedure, the amount and cost of bivalirudin used per procedure is difficult to predict.



Risk of immunological reaction. According to its package insert, use of bivalirudin has been associated with severe
allergic reactions and publicly available safety data has reported two anaphylaxis deaths.

The REG1 Anticoagulation
System

Overview

REG1 is a two-component system consisting of pegnivacogin, an anticoagulant targeting coagulation Factor IXa, or FIXa, and its specific active control agent, anivamersen, both of which are administered
solely by IV bolus injection.

Pegnivacogin is a single-stranded oligonucleotide conjugated to polyethylene glycol, or PEG.
Pegnivacogin is a potent anticoagulant that binds to FIXa with high affinity and specificity, thereby preventing blood clot formation and progression. Pegnivacogin is administered prior to the start of a PCI procedure and achieves its maximal
anticoagulant effect within five minutes of injection. This anticoagulant effect lasts for 24 hours or more unless modulated or eliminated by the specific active control agent.

In developing pegnivacogin, we targeted FIXa for the following reasons:



FIXa controls the rate of thrombin formation so inhibiting it should more effectively slow or prevent clotting than inhibition of FXa or thrombin;

FIXa is seven times more potent than FXa and 60 times more potent than thrombin, so less drug is needed to achieve a desired anticoagulant effect; and



due to the biochemical nature of the interactions of FIXa in the clotting process, aptamers are the only known means to achieve controllable inhibition
of FIXa.

Anivamersen is an oligonucleotide, a biological polymer consisting of a relatively small number of
nucleotides chemically bound in a linear sequence that forms a chain-like structure, or strand, that is complementary to a portion of pegnivacogin and has no pharmacologic activity other than to bind to pegnivacogin. When anivamersen binds to
pegnivacogin, it changes the shape of pegnivacogin so that it can no longer bind to FIXa, thereby permanently eliminating its anticoagulant activity within minutes. At the end of a PCI procedure, when the antithrombotic effect of the pegnivacogin is
no longer needed, anivamersen is administered to rapidly and precisely reduce or eliminate it.

The effect of anivamersen on
pegnivacogin is solely dependent on the amount of anivamersen administered relative to the dose of pegnivacogin. As a result, and unlike heparin and bivalirudin, REG1s anticoagulation reversal is independent of an individual patients
metabolism or health. By adjusting the dose of anivamersen relative to pegnivacogin, the anticoagulant effect of pegnivacogin can be precisely and rapidly controlled or eliminated.

Competitive Advantages

We believe that REG1 has the potential to become the standard of care for anticoagulation therapy in PCI and other cardiovascular procedures because it gives physicians precise, on-demand control over
anticoagulation levels. We believe the key advantages of REG1 over existing therapies are the following:



Reduced ischemic events. Because the anticoagulant effect of REG1 can be precisely controlled or eliminated, REG1 allows a higher level
of anticoagulation to be used safely during the PCI procedure when needed most. A higher level of anticoagulation will reduce the occurrence of ischemic events such as death, MI, stroke or the need for revascularization.



Reduced major bleeding events. REG1s anticoagulant effect can be modulated or eliminated at the end of the PCI procedure, when it
is no longer necessary or desirable, to reduce the risk of major bleeding events. Once the anticoagulation effect is reduced or eliminated, ordinary clotting can occur.



Precise and predictable dosing. Because REG1s effect is independent of an individual patients metabolism or health, dosing is
precise and predictable, thereby eliminating the need for time-consuming and costly patient monitoring during and after PCI.



Broad applicability. REG1s use in PCI is unrestricted for high risk patients such as those with kidney or liver impairment.



Shorter procedure and recovery times. REG1 significantly reduces the time between the end of the PCI procedure and the time the arterial
catheter sheath can be pulled safely, as well as the time between the end of the procedure and the time the patient is ambulatory. As a result, we believe that overall procedure times can be significantly reduced, resulting in shorter hospital
stays.



Improved patient outcomes and experience. We believe that REG1 will improve patient outcomes by reducing the overall number of ischemic
events and the risk of major bleeding events. Also, REG1 can shorten procedure and recovery times and reduce the need for VCDs or other procedure-related follow-up interventions and re-hospitalizations. Because procedure and recovery times will be
reduced and patients will experience fewer complications and will be able to leave the hospital more quickly, we believe that the patient experience will also be improved.



Increased staff and facility efficiency. Shorter procedure times will increase staff and facility efficiency by allowing more patients to
be treated with reduced staff attention and intervention necessary after the procedure ends. We believe that REG1 will also enhance efficiency by reducing complications that may require emergency intervention or re-hospitalization, such as the need
for revascularizations or major blood transfusions.

REG1 has been studied in three Phase 1 trials
involving a total of 174 subjects and one Phase 2a proof-of-concept PCI trial involving 26 subjects. These early clinical trials collectively demonstrated that:

a single injection of pegnivacogin reliably produced anticoagulation in humans for more than 24 hours;



a single injection of anivamersen partially or completely reversed pegnivacogin anticoagulation rapidly based on the ratio of the anivamersen dose to
the pegnivacogin dose;



the anticoagulation effect of REG1 can be measured with existing standard tests;



pegnivacogin and anivamersen were well-tolerated;



elective PCI could be performed successfully using REG1 therapy; and



arterial catheter sheaths could be removed at the end of PCI procedures.

RADAR Trial

In November 2010, we completed the RADAR trial involving 640 subjects at 69 enrolling sites in the United States, Canada, France, Germany, Poland and the Netherlands. RADAR was an adaptive design,
randomized, partially-blinded, dose-ranging trial assessing the safety and efficacy of REG1 in patients with UA and N-STEMI intended for PCI. Standard of care heparin, either UFH or LMWH, was the comparator. Subjects received open-label pegnivacogin
at 1mg/kg, followed by a blinded dose of anivamersen to achieve 25%, 50%, 75% or 100% levels of pegnivacogin reversal. GPIIb/IIIa inhibitor use was stipulated for the heparin arm per standard of care guidelines and for provisional use in the REG1
arm for procedural or angiographic complications. Arterial catheter sheaths were to be removed at the end of the catheterization in the REG1 arm and per standard of care in the heparin arm. The demographics and background therapies in RADAR were
similar to prior ACS studies with heparin and bivalirudin.

RADAR had several objectives, including the following:



determine the clinically acceptable dose range of anivamersen that reliably reverses the anticoagulant effect of pegnivacogin as measured by bleeding
events;

confirm that near-complete FIXa inhibition was achieved with pegnivacogin at the 1 mg/kg dose; and



measure various pharmacoeconomic factors such as the feasibility of early arterial catheter sheath removal, time to sheath removal and time to patient
ambulation, compared to standard of care heparin.

The primary endpoint of RADAR was the composite incidence
of major and minor bleeding through day 30. The key secondary endpoint was the proportion of subjects with a composite of ischemic events through day 30. In addition, a predefined analysis of the primary and secondary endpoints was made at 48 hours
to simulate hospital discharge. All of these endpoints were adjudicated by an independent clinical events committee.

As part
of the adaptive design to determine the effective dose response for anivamersen, RADAR included assessments by an independent data safety and monitoring board, or DSMB, at prescribed enrollment milestones. The DSMB was empowered to eliminate one or
more of the anivamersen doses if excessive ischemic event rates

were observed or, as was expected for the lowest anivamersen dose, excessive bleeding event rates were observed. If an anivamersen dose was eliminated as part of the adaptive design, the
remaining REG1 subjects intended for the discontinued group would be randomized into a continuing anivamersen dose. As contemplated by the adaptive design, the DSMB ended the lowest anivamersen dose of 25% reversal early in the study due to
excessive bleeding events.

RADAR demonstrated that REG1 was well-tolerated and, excluding the 25% reversal group, that there
was no relevant difference in the overall incidence of treatment-emergent adverse events or serious adverse events between the REG1 arm and the heparin arm or among the remaining REG1 treatment groups.

At day 30, the 100% reversal dose significantly reduced total and major bleeding events as compared to the 25% REG1 reversal dose with a
stepwise numerical reduction in major bleeding at doses of anivamersen greater than 50% reversal.

At 48 hours, the 100%
reversal dose was statistically superior to both heparin (p=0.045) and the 25% reversal dose (p<0.001) in reducing major bleeding events. At anivamersen doses greater than 50% reversal, a decrease in the number of subjects with major bleeding
events was observed. There was a trend towards reduction in total bleeding in the 100% reversal group, as compared to heparin (p=0.07). Among the REG1 groups, there was an anivamersen dose-dependent numerical decrease in the number of subjects with
total bleeding from time of randomization to 48 hours. The results of RADAR confirmed that there was a consistency of effect across total and major bleeding events with doses above 50% reversal numerically better than heparin. The 100% reversal dose
was statistically superior to the 25% reversal dose in reducing the incidence of total bleeding (p<0.001), which also confirmed the dose response. Based upon the odds ratio, which is a measure of the effect size, the REG1 100% reversal group
demonstrated a 60% reduction in major bleeding events as compared to standard of care heparin.

The results of major bleeding
events reported in RADAR for heparin and for REG1 at 48 hours are summarized in the following table:

All REG1 patients received the same pegnivacogin dose. An
overall composite ischemic event rate was calculated by combining the composite ischemic events from each REG1 group. In the overall REG1 arm, there was a numerical reduction in the rate of composite ischemic events at day 30 to 3.0% compared to
5.7% for patients in the heparin arm. Overall, 1.9% of the subjects in the REG1 arm had composite ischemic events at 48 hours compared to 5.0% of the subjects in the heparin arm. A consistent effect on ischemic events was seen at 48 hours, 30 days
and in those patients undergoing PCI in the REG1 groups, as compared to heparin. For those REG1 subjects undergoing PCI, no evidence of clots on guide wires or catheters was reported. Based upon the odds ratio, which is a measure of the effect size,
the REG1 group demonstrated a 66% reduction in ischemic events as compared to standard of care heparin.

Composite ischemic events for the heparin arm and the REG1 arm from time of randomization to
48 hours are shown in the table below:

*

Odds Ratio = 0.34

Source: RADAR Clinical Study
Report

Measured levels of coagulation corresponded well to targeted levels of reversal after anivamersen dosing. These results
indicate the ability to reliably predict reversal with the use of REG1, even when treating physicians are blinded to the level of reversal and the coagulation measurements.

REG1 also demonstrated a number of potential pharmacoeconomic effects. Arterial catheter sheaths were removed a median of one hour after catheterization compared to a median of 3.8 hours in the heparim
arm. Arterial catheter sheaths were removed a median of 24 minutes after the procedure in the REG1 arm compared to a median of three hours in the heparin arm. Subjects were ambulated approximately a median of 2.8 hours after arterial catheter sheath
removal in the REG1 arm compared to a median of 5.7 hours after arterial catheter sheath removal in the heparin arm. These results are summarized below:

Source: RADAR Clinical Study Report

Late in the trial, three REG1 subjects experienced severe allergic events. These events occurred 3 to 20 minutes after administration of pegnivacogin and ranged from a subject with a mild skin reaction to
one subject who needed extended hemodynamic support. Based on a blinded assessment of bleeding and ischemic events at that time, it was determined that a sufficient number of endpoint events had occurred to meet the objectives of the trial and the
trial was deemed complete. Following the occurrence of the allergic events, a detailed analysis of possible causes was performed. We determined that all three subjects were experiencing activation of their immunological system prior to receiving
REG1 treatment and had a history of allergic reactions. We also determined that the REG1 used in these patients conformed to our specifications, was not contaminated,

mishandled or stored incorrectly and that no changes to the formulation had occurred. Based on non-human primate studies, we concluded that there was no clinical or biomarker evidence of
intravascular immune pathway activation. We also re-examined the complete REG1 clinical database and found no evidence of serious allergic reactions within the remainder of the REG1 development program. Following completion of our investigations and
submission of a risk minimization action plan, the FDA and the EMA agreed that we could proceed to a Phase 3 trial and that no additional exclusion criteria, and no special dosing, pre-treatment or pre-screening requirements were necessary.
Additionally, in REGULATE-PCI investigators will receive training on the identification and proper treatment of allergic reactions and blood samples from all subjects will be collected and stored for future reference in the event they are needed for
analysis.

REGULATE-PCI Trial

Based on these clinical results and after discussion with the FDA and the EMA, we intend to commence the REGULATE-PCI trial in the second half of 2013. REGULATE-PCI, if successful, will serve as the basis
for product registration applications worldwide.

REGULATE-PCI will be a single, open-label Phase 3 trial comparing REG1 to
bivalirudin in subjects undergoing PCI as an elective procedure or for the treatment of UA or N-STEMI. The first 1,000 subjects enrolled will be limited to those undergoing elective PCI or PCI as a treatment for UA. REGULATE-PCI will enroll
approximately 13,200 subjects at approximately 500 investigational sites worldwide. The number of subjects was determined so that the achievement of the primary efficacy endpoint of a 20% reduction in the occurrence of ischemic events versus
bivalirudin would be statistically significant. The primary safety endpoint of REGULATE-PCI is non-inferiority to bivalirudin for the occurrence of major bleeding events. As an adaptive design trial, REGULATE-PCI permits a one-time increase in
subject population, if necessary, at the time of 50% enrollment to maintain adequate trial size for statistical significance. Subjects will be randomized once it is determined that they will undergo PCI. REGULATE-PCI has limited exclusion criteria
and is designed to be conducted using real life conditions and background therapies recommended by current standards of care. It will allow both femoral and radial approaches to vascular access as determined by the investigator. Investigators will
also be allowed to use VCDs.

The primary endpoint of REGULATE-PCI is the efficacy of REG1 compared to bivalirudin for
preventing a composite of death, nonfatal MI, nonfatal stroke and urgent target lesion revascularization, or TLR, through day three. The key secondary objective is to determine the safety of REG1 compared to bivalirudin as measured by major bleeding
events through day three. Subjects will be followed for 30 days. Subjects will receive on an open-label basis either pegnivacogin at the RADAR dose of 1mg/kg or bivalirudin at the labeled dose. The REG1 subjects will receive 0.5 mg/kg of
anivamersen, representing approximately 80% reversal, at the end of the PCI procedure. Bivalirudin subjects will have their drug discontinued at the end of the PCI procedure or otherwise in accordance with standard of care. Investigators will have
the discretion to increase the reversal to 100% for REG1 subjects if they determine that the subject has an increased risk of a major bleeding event or in the event of a bleeding complication after the removal of the arterial catheter sheath.
Subjects will receive standard guidelines-based background therapy and provisional GPIIb/IIIa inhibitors in both groups. Arterial catheter sheaths will be removed two to ten minutes after the administration of anivamersen in the REG1 arm at the end
of the PCI and two to four hours from the end of the PCI for the bivalirudin arm, per standard of care. Pharmacoeconomic endpoints including time in catheterization laboratory, time to sheath removal, time to ambulation and time to hospital
discharge will be captured.

REGULATE-PCI will include three interim analyses. The first interim analysis will occur after
enrollment of 1,000 subjects and is expected to occur by the end of the second quarter of 2014. At this time, the DSMB will evaluate general safety of the subjects enrolled to that point in the REG1 arm and, if the results are satisfactory, will
extend trial enrollment to include UA and N-STEMI subjects. The second interim analysis will be another general safety assessment by the DSMB after 25% of the subjects are enrolled, which is expected to occur by the end of the third quarter of 2014.
At that time, the DSMB will recommend the continuation or discontinuation of REGULATE-PCI based on its evaluation of the safety results in the REG1 arm. The final interim analysis will be performed after 50% of the subjects have been enrolled, which
is expected to occur by the end of 2014. At that

time, the DSMB will assess the general safety of REG1 and will perform an analysis of its efficacy. If the DSMB determines that REG1 is not safe or that it is futile to continue the trial because
of a lack of efficacy, the trial will be terminated. On the other hand, if the DSMB determines REG1 is safe and its efficacy is overwhelmingly superior to bivalirudin, a positive outcome will be declared and the trial will be considered completed.
Also at that time, since REGULATE-PCI is an adaptive design study, the DSMB may recommend an increase of total trial size based on a comparison of actual endpoint event rates to assumed rates to maintain the statistical significance of the trial
results. Unless terminated early or extended as described above, we expect to complete REGULATE-PCI by the end of 2015 with results available in early 2016.

We have had extensive discussions with the FDA regarding our REGULATE-PCI trial, including the trial design, the trial protocol, inclusion-exclusion criteria, trial population, endpoint definition,
duration of follow-up, statistical analysis plan and interim analyses. Because of the extent of these discussions, and based on the FDAs view that we would obtain no additional benefit from pursuing a Special Protocol Assessment, or SPA, for
the trial, we determined not to seek an SPA from the FDA for the REGULATE-PCI trial.

Other REG1 Indications

We believe that REG1 has potential for use in other PCI and interventional cardiovascular procedures, such as OHS, PCI
as a treatment for STEMI, and TAVI, all of which are indications in which bivalirudin is not currently approved for use. These indications are described below.

OHS

We intend to develop REG1 for use in patients undergoing OHS as a
replacement for the heparin  protamine combination. Based on information obtained from publicly available OHS procedure registries, we estimate that approximately 600,000 OHS procedures were performed in the United States, the United Kingdom,
France, Germany, Italy, Spain and Japan in 2012. If our proof-of-concept human trials are successful, we plan to proceed to pivotal trials for approval of this indication. The EMA has agreed with our proposed clinical development program and we are
currently in discussion with the FDA regarding this program. Because development of this application is at an early stage, we have not filed an IND with the FDA. We intend to file an IND for this application of REG1 after completion of our
proof-of-concept human trial.

An extremely high level of anticoagulation is required in OHS to prevent life-threatening
clotting, especially when a pump is used to maintain blood flow during the procedure. Heparin is used as the anticoagulant in most OHS procedures. Protamine must be used in OHS patients to reduce heparins anticoagulant effect even though
protamine is unpredictable and may result in additional complications. OHS patients are subject to intense post-procedure monitoring for major bleeding events. We believe a drug that achieves an optimal level of anticoagulation that can be precisely
and predictably controlled or reversed at the end of the procedure and which does not have the significant side effects associated with heparin and protamine would result in improved outcomes for patients undergoing OHS. As a result, REG1 has the
potential to become the standard of care anticoagulant for use in OHS.

In 2008, we commenced an exploratory Phase 2a
feasibility trial of REG1 in patients undergoing off-pump coronary arterial bypass grafting, or CABG, which was intended to enroll ten subjects. The trial was stopped due to clotting in one of three bypass grafts placed in the first study subject so
we could assess the cause of clotting, reassess and optimize the protocol, and complete further preclinical development and delineation of optimum methods of use of REG1 in CABG. As a result of our assessments and additional work, future testing of
REG1 in CABG patients will be done as a part of the OHS program under a significantly modified protocol.

STEMI

We intend to develop REG1 for use in patients undergoing PCI as a treatment for STEMI. Based on information obtained from
the Healthcare Utilization Report 2010, we believe that approximately 700,000 PCI procedures were performed worldwide in 2010 for the treatment of STEMI. STEMI patients are more at risk if an ischemic event occurs than other patients undergoing PCI
treatment because they generally present with significant clotting. As a result, a higher level of anticoagulation is necessary to treat these patients effectively.

For these patients, the risk of ischemic events significantly outweighs the risk of major bleeding events. We believe a drug that can safely achieve a high level of anticoagulation would result
in improved outcomes for STEMI patients undergoing PCI. As a result, REG1 has the potential to become the standard of care anticoagulant for use in this patient group. Because development of this application is at an early stage, we have not filed
an IND with the FDA for this application of REG1.

TAVI

We intend to develop REG1 for use in patients undergoing TAVI. TAVI is an emerging interventional cardiovascular procedure in which
myocardial valves are repaired or replaced through a catheter rather than OHS. While TAVI has the potential to be a safer alternative to OHS, TAVI presents many of the same risks applicable to PCI procedures as well as those applicable to OHS. The
risk of stroke in TAVI is significantly greater than in OHS and therefore TAVI is not used if a patient can tolerate OHS. Also, the catheters used in TAVI procedures are approximately four to five times larger in diameter than those used in PCI,
increasing the potential for arterial damage during the procedure. Because of these factors, in TAVI procedures heparin is dosed in similar amounts to OHS. However, because of the increased stroke risk, protamine is usually not used at the end of
the procedure to reverse heparins anticoagulant effect, thereby exposing the patient to a high risk of a major bleeding event. In addition, because the stroke risk persists for up to two weeks, a TAVI patient may require sub-acute
anticoagulant treatment to prevent a possible stroke. We believe a drug that achieves an optimal level of anticoagulation and that can be precisely and predictably controlled or reversed would result in improved outcomes for patients undergoing TAVI
and could dramatically expand the use of TAVI. As a result, REG1 has the potential to become the standard of care anticoagulant for use in TAVI. In addition, REG2 has potential application for use in TAVI patients due to its extended release
formulation. Because development of this application is at an early stage, we have not filed an IND with the FDA for this application of REG1.

Our Proprietary Technology Platform

We are pioneering the discovery and development of two-component drug systems consisting of a therapeutic aptamer and its specific active control agent. Our aptamers are single strands of nucleic acids,
or oligonucleotides, that are chemically synthesized. Unlike other oligonucleotides, which are designed to control gene expression, an aptamer has a unique geometric shape that binds specifically and tightly to a target protein molecule, leading to
inhibition of the targets activity. Aptamers have been discovered that interact with essentially every class of therapeutic protein target. An aptamers pharmacologic activity can be controlled by interaction with a complementary
oglionucleotide, which we term a specific active control agent. When the specific active control agent binds to the aptamer, it changes the aptamers shape thereby eliminating its therapeutic activity. Our founder co-invented our aptamer
control technology to address the unmet medical need for a controllable antithrombotic therapy that could be rapidly modulated or eliminated.

We believe we have the leading position in the development of actively controllable aptamer therapeutic systems, including expertise in aptamer discovery, active control agent design, oligonucleotide
chemistry, strong aptamer and active control agent intellectual property rights, including exclusive rights to key patents relating to control of aptamer activity in the body, and disciplined aptamer and active control agent drug discovery and
development processes. Central to achieving our goals is the know-how that we have accumulated in aptamer discovery and control agent design and how the specific chemistries we utilize behave in the clinical setting.

We believe that the following aspects of our technology platform give us a competitive advantage:



a proven discovery team including the co-inventor of active aptamer control agent technology;



an exclusive license to the patents covering active aptamer control agent technology, which include broad claims directed toward nucleic acid ligands
and methods to control aptamer activity by administration of active control agents;



a commercial license to the combinatorial chemistry technology platform, or SELEX, for aptamer discovery and development;

the know-how to identify, isolate and optimize therapeutic aptamers and their active control agents, which has led to the discovery of multiple product
candidates;



a proven pharmaceutical development team with experience in the development of efficient and economical manufacturing processes for aptamers and active
control agents; and



an extensive clinical database of systemic aptamer use, which gives us unparalleled expertise in the discovery of new two-component aptamer-based
product candidates.

The disciplined approach we take to the discovery and development of controllable
aptamer therapeutic systems is as important as the assets assembled to execute on our plans. Every aspect of our development process, including the evaluation of a therapeutic opportunity, the identification of a specific target protein, the
discovery of a therapeutic aptamer and the optimization of active control agents, is designed to increase our probability of success. Our disciplined approach is summarized in the following four steps:

Step 1Evaluation of Opportunities

The initiation of our discovery and development efforts is based on rigorous scientific and business criteria, including:



clear scientific evidence of the role that a specific target protein plays in a disease;



scientific evidence to support the belief that the use of an aptamer to inhibit the target protein will provide for a novel mechanism of action
compared to existing therapies;



clinical evidence that the ability to control the aptamers activity in the treatment of the disease will address an unmet medical need or
potentially provide for a superior treatment over existing therapies; and



existence of a significant commercial opportunity.

Our evaluation criteria potentially apply to a broad range of target proteins, allowing us to focus on product candidates that we believe have a high probability of clinical and commercial success.

Once we decide to pursue a specific treatment, we use a proprietary methodology to identify and optimize lead aptamer and
active control agent pairs for development.

Step 2Aptamer Identification

We identify aptamers using the SELEX process, licensed to us by Archemix Corporation, or Archemix. The SELEX process enables us to incubate a large number of nucleic acid sequences with a specific target protein to more efficiently identify aptamers with the necessary
structural and binding properties. Additionally, we use a proprietary process to establish the optimal conditions for performing the SELEX process to each target protein, which we believe provides for a high probability of success in identifying potent aptamers.

Step 3Control Agent Identification

Once we have identified a potential aptamer candidate, we design potential active control agents based upon rules of Watson-Crick base pairing, the fundamental chemical principles that describe the
binding of complementary strands in DNA and RNA molecules to each other. We have developed significant understanding and know-how of the interaction of active control agents with aptamers, which we believe enables us to design and screen potential
active control agents with a high probability of success.

Step 4Aptamer-Control Agent Optimization

The final step in our discovery process is the optimization of the aptamer and active control agent for their
pharmacokinetic and pharmacodynamic properties and ease of manufacture. We use our extensive knowledge of oligonucleotide chemistry and clinical performance of controllable aptamer therapeutic systems to:



optimize the aptamer size and use of stabilization chemistries within the aptamer to provide for a potent, well-tolerated aptamer with a half-life
matched to its intended clinical use that can be manufactured cost effectively;

identify the appropriate carrier for the aptamer, such as PEG, to provide for desirable pharmacokinetic and distribution properties while maintaining
the desired potency; and



optimize the active control agent to achieve a suitable half-life, to provide for potent modulation or elimination of the aptamers therapeutic
activity and to permit cost effective manufacture.

Aptamer technology has evolved significantly since first
generation aptamers were described in 1990. Many of the early aptamers were chemically and metabolically unstable, were potentially immunologically active and were prohibitively expensive to produce. Our product candidates consist of third and
fourth generation aptamers that have significantly improved pharmaceutic and pharmacokinetic stability and have not shown immunological activity in a wide range of tests. Due to advances in synthetic techniques, these aptamers can be economically
produced using readily available synthesis technology.

Our Other Product Candidates

Using our proprietary technology platform, we have developed a pipeline of other product candidates which are described below.

REG3

REG3 consists of a novel, first-in-class GPVI inhibitor and its specific active control agent. Increased levels of GPVI are present in a wide range of platelet-mediated diseases including ACS, stroke,
rheumatoid arthritis and diabetic vasculopathy. In recent years, GPVI has emerged as a promising anti-platelet target. REG3 uses aptamer technology to bind to GPVI thereby inhibiting its function. We believe that REG3s novel mechanism of
action will enable it to successfully inhibit GPVI and provide an effective treatment for these conditions. REG3 is being developed as an injectable for sub-acute GPVI inhibition. REG3s specific active control component is designed to permit
modulation or elimination of the GPVI inhibition, if necessary, to optimize dosing and minimize unwanted side effects that might result from GPVI inhibition. We plan to initiate a Phase 1 study of REG3 in 2014.

REG2

The active components of REG2 are identical to that of REG1 except that the pegnivacogin is formulated for subcutaneous depot injection for extended release. REG2 is intended to provide a controllable
level of anticoagulation for up to two weeks for sub-acute uses, especially where a patient may be unable to swallow an oral anticoagulant. We are developing REG2 for use in venous thrombosis indications such as VTE prophylaxis in patients
undergoing abdominal surgery. REG2 could also be used as a sub-acute anticoagulant treatment for TAVI patients or for bridging patients who are unable to take oral anticoagulants for a period of time before or after a procedure. In REG2, anivamersen
is intended for use as an active control agent if needed. We have completed a single escalating dose Phase 1 clinical trial of REG2 and plan to conduct additional clinical testing in the future.

Our Strategy

Our
strategy is to discover and develop novel, first-in-class controllable antithrombotic drug systems for use in acute and sub-acute cardiovascular and other indications that we believe are underserved by existing therapies. The key elements of our
strategy are:



Complete the development and obtain regulatory approval for the first indication of REG1 in the United States, Europe and other
countries.We expect to commence REGULATE-PCI in the second of half of 2013. If successfully completed, we intend to seek approval for the first indication of REG1 in the United States, Europe and other countries. We have
assembled an experienced team with a successful track record of managing global clinical development activities, obtaining regulatory approvals worldwide for new drugs and maintaining compliance with international regulations governing the
development, sales, marketing and distribution of pharmaceutical products. We believe we have the expertise and capacity to manage a global development program without local partners.

Commercialize REG1 in its first indication in the United States, Europe and other countries alone or with a strategic
partner. Because REG1 is a hospital-based acute care product, we believe that it is feasible for us to commercialize the first REG1 indication with a relatively small specialty sales force calling on a targeted group of
hospital-based interventional cardiologists. If REG1 is approved, we intend to commercialize REG1 in its first indication in the United States by building a commercial infrastructure or by utilizing contract reimbursement specialists, sales people
and medical education specialists. We may seek to augment our commercial efforts by entering into a collaboration with a pharmaceutical company, if such a collaboration is available on attractive terms. Outside of the United States, we likely will
seek to commercialize REG1 through distribution or other collaboration arrangements.



Develop and commercialize other applications for REG1. We intend to develop REG1 for use in additional cardiovascular procedures, such as
OHS, PCI as a treatment for STEMI, and TAVI. We believe REG1s two-component anticoagulant system addresses unmet needs in these markets.



Advance the other product candidates in our pipeline. We intend to develop product candidates in our pipeline beyond REG1, including REG3
and REG2.



Seek joint development agreements for our other product candidates or new treatment targets. We intend to seek partners to
assist us in the development of REG3 and REG2, as well as any new product candidates we discover. We also intend to seek collaborations with other life sciences companies that may desire to use our proprietary technology to discover and develop
novel treatments in their areas of clinical interest.

Third-Party Suppliers and Manufacturers

We do not have a manufacturing infrastructure and do not intend to develop one. We have agreements with our third-party manufacturers, or
CMOs, to supply bulk drug substances for our product candidates and with third parties to formulate, package and distribute our product candidates. Our employees include professionals with expertise in pharmaceutical manufacturing development who
oversee the manufacture and distribution of our product candidates by third-party companies. We believe that we have sufficient amounts of REG1 on hand to complete the REGULATE-PCI trial. All of the drug substances used in our product candidates are
manufactured by single suppliers. While we have not experienced any supply disruptions, the number of oligonucleotide manufacturers is limited. In the event it is necessary or advisable to acquire supplies from an alternative supplier, we might not
be able to obtain them on commercially reasonable terms, if at all. It could also require significant time and expense to redesign our manufacturing processes to work with another company. Formulation and distribution of our finished product
candidates are also conducted by a single supplier but we believe that alternative sources for these services are readily available on commercially reasonable terms.

In July 2006, we entered into a supply and service agreement with Agilent Technologies, Inc., or Agilent, which was amended in July 2011, for the manufacture of pegnivacogin and anivamersen bulk drug
substance for use in the clinical development of REG1. Drug substances are manufactured pursuant to a good manufacturing practices quality agreement entered into in May 2010. Manufacture of bulk drug substance lots is on a purchase order basis, with
no minimum purchase obligation. The supply and service agreement has an indefinite term and expires when all services thereunder have been completed. Agilent may terminate the agreement with or without cause upon 180 days prior written notice to us.
We may terminate the agreement if Agilent is unable to timely meet our purchase orders or Agilents quoted prices are more than 110% of those available from a third party. Either party may terminate the agreement upon written notice if the
other party is in breach of a material provision of the agreement and such breach is not cured within 60 days after receipt of written notice of the breach.

In December 2006, we entered into a license, manufacturing and supply agreement with Nektar Therapeutics, or Nektar, for the supply of PEG used in the manufacture of pegnivacogin. We must provide Nektar
with a rolling forecast of our anticipated requirements for the succeeding six quarters, with respect to pre-commercial supply, or eight quarters, with respect to commercial supply, with a required lead time to commit to and guarantee availability
of the reagent at an agreed upon pricing structure, which is subject to revision on an

annual basis. In addition, we have agreed to pay Nektar specific development and commercial milestones and a specific royalty on product sales. See License AgreementsNektar License
and Supply Agreement.

In March 2012, we entered into a clinical supply agreement with Althea Technologies, Inc., for the
formulation and packaging of pegnivacogin and anivamersen for use in our clinical trials. The formulation and packaging is conducted pursuant to a quality agreement entered into in January 2012. Formulation and packaging services are provided on a
purchase order basis, with no minimum purchase obligation. The clinical supply agreement has an indefinite term and expires when all services thereunder have been completed. The agreement may be terminated by us with or without cause on 30 days
written notice, immediately by either party upon the occurrence of certain bankruptcy events related to the other party, upon 30 days written notice by either party if the parties fail to agree on a change in the scope of the agreement, or upon
written notice by one party in the event of a material breach by the other party that is not cured within 30 days or such additional time that may be reasonably necessary to cure such breach if commenced within such 30-day period and diligently
pursued to completion.

In November 2007, we entered into a development and supply agreement for REG3 bulk drug substance with
Avecia Biotechnology, Inc., which expired in November 2009. We anticipate entering into extension of this agreement or a new agreement to manufacture REG3 for our planned Phase I study. Manufacture of bulk drug substance lots is on a purchase order
basis, with no minimum purchase obligation.

Except for the agreement with Nektar, all of the agreements described above relate
solely to the clinical development of our product candidates. In the event that we obtain marketing approval for a product candidate, we will be required to enter into separate agreements for the commercial production and distribution and
manufacturing of that product.

Intellectual Property

We believe that we have a strong patent portfolio and substantial know-how relating to REG1, our other product candidates and our proprietary technology platform. Our patent portfolio, described more
fully below, includes claims directed to aptamers, pharmaceutical compositions containing aptamers, aptamer formulations, methods for altering the affinity of an aptamer for a target molecule and for treating disease and disorders, as well as
methods of manufacturing aptamers and aptamer formulations. As of April 29, 2013, we are the owner of record of five issued or allowed U.S. patents and six issued or allowed non-U.S. patents, as well as the licensee of at least nine issued or
allowed U.S. patents and at least ten issued or allowed non-U.S. patents. We are actively pursuing an additional 13 U.S. patent applications, of which four are provisional and nine are non-provisional, one international patent application and 39
non-U.S. patent applications in twelve jurisdictions as the owner of record, in addition to at least two U.S. patent applications and 14 non-U.S. patent applications under license.

We strive to protect the proprietary technology that we believe is important to our business, including our proprietary technology
platform, our product candidates and our processes. We seek patent protection in the United States and internationally for our products, their methods of use and processes of manufacture, and any other technology to which we have rights, where
available and when appropriate. We also rely on trade secrets that may be important to the development of our business.

Our
success will depend on the ability to obtain and maintain patent and other proprietary rights in commercially important technology, inventions and know-how related to our business, the validity and enforceability of our patents, the continued
confidentiality of our trade secrets as well as our ability to operate without infringing the valid and enforceable patents and proprietary rights of third parties. We also rely on continuing technological innovation and in-licensing opportunities
to develop and maintain our proprietary position.

We cannot be sure that patents will be granted with respect to any of our
pending patent applications or with respect to any patent applications we may own or license in the future, nor can we be sure that any of our existing patents or any patents we may own or license in the future will be useful in protecting our
technology. For this and more comprehensive risks related to our intellectual property, please see Risk FactorsRisks Relating to Our Intellectual Property.

The term of individual patents depends upon the legal term of the patents in the countries
in which they are obtained. In most countries in which we file, the patent term is 20 years from the date of filing the non-provisional priority application. In the United States, a patents term may be lengthened by patent term adjustment,
which compensates a patentee for administrative delays by the U.S. Patent and Trademark Office, or PTO, in granting a patent, or may be shortened if a patent is terminally disclaimed over an earlier-filed patent.

The term of a U.S. patent that covers an FDA-approved drug may also be eligible for patent term extension, which permits patent term
restoration as compensation for the patent term lost during the FDA regulatory review process. The Hatch-Waxman Amendments permit a patent term extension of up to five years beyond the expiration of the patent. The length of the patent term
extension is related to the length of time the drug is under regulatory review. A patent term extension cannot extend the remaining term of a patent beyond a total of 14 years from the date of product approval and only one patent applicable to an
approved drug may be extended. Similar provisions are available in Europe and other foreign jurisdictions to extend the term of a patent that covers an approved drug. When possible, depending upon the length of clinical trials and other factors
involved in the filing of a new drug application, or NDA, we expect to apply for patent term extensions for patents covering our product candidates and their methods of use.

The patent portfolios for our proprietary technology platform and our three most advanced product candidates as of April 29, 2013 are summarized below.

Our Proprietary Technology Platform

Our active aptamer control agent technology was co-discovered by Dr. Christopher P. Rusconi, our chief scientific officer, in his prior role at Duke University, or Duke. Those discoveries are
disclosed and claimed in a patent portfolio owned by Duke, or the Duke portfolio, and exclusively licensed to us, on terms described more fully below. The Duke portfolio includes broad claims directed to aptamers and pharmaceutical compositions
containing aptamers, as well as methods for modulating coagulation. By stage and geographic focus, the Duke portfolio includes issued U.S. patents, such as U.S. Patent Nos. 7,312,325; 7,776,837; 7,300,922; 8,143,233 and 8,283,330, pending U.S.
patent applications, such as U.S. Patent Application Nos. 11/789,992 and 13/428,352, and corresponding issued and foreign national or regional counterpart patents or applications. The issued and pending applications include broad subject matter
directed to modulation of aptamer function in the body by a number of different methods. The most significant issued patent within the Duke portfolio, U.S. Patent No. 7,300,922, is expected to expire in 2023, as a result of patent term adjustments.
If issued, the last to expire pending patent application within this portfolio would expire in 2022, excluding any patent term adjustments or extensions.

Archemix owns or controls a patent portfolio, or the Archemix portfolio, and related know-how directed to the proprietary SELEX method for identifying nucleic acid ligands and directed broadly to nucleic acid ligand compositions, licensed to us under terms described more fully below. By stage
and geographic focus, the portfolio includes issued U.S. patents and corresponding foreign national or regional counterpart patents or applications. The most significant issued patent within the Archemix portfolio, U.S. Patent No. 6,011,020 relating
to pegylated aptamers, is expected to expire in January 2017. We have a license from Archemix under which we possess rights in certain patent rights and know-how owned or controlled by Archemix, as described more fully below, including an exclusive
commercial license and a non-exclusive research license to the SELEX processes for identifying aptamers for
use in products that contain an aptamer and an active control agent for use in the treatment of certain coagulation-related diseases or conditions in humans.

REG1

The patent portfolio for REG1 includes wholly owned patents
and patent applications directed to aptamers, pharmaceutical compositions containing aptamers, aptamer formulations, methods for modulating coagulation and treating coagulation-related diseases utilizing aptamers, and methods of manufacturing
aptamers. It includes issued U.S. Patent Nos. 7,304,041; 7,723,315, 8,389,489 and 7,531,524, pending U.S. patent applications, and corresponding foreign national or regional counterpart patents or applications. The most significant issued

patents within this portfolio are the issued U.S. patents referenced above, all of which are expected to expire in

2025, excluding any additional term for patent term extensions. If issued, the last to expire pending patent application within this portfolio would expire in 2033, excluding any additional term
for patent term adjustments or patent term extensions.

REG3

The patent portfolio for REG3 includes wholly owned patents and patent applications. It includes claims directed to aptamers,
pharmaceutical compositions containing aptamers, aptamer formulations, methods of treating a platelet-mediated disorder and methods of modulating platelet function. It includes issued U.S. Patent No. 8,318,923, pending U.S. patent applications, and
corresponding foreign national or regional counterpart applications. The last to expire issued patent is expected to expire in 2030, excluding any patent term adjustments or extensions. If issued, the last to expire pending patent applications are
expected to expire in 2033, excluding any patent term adjustments or extensions.

REG2

The REG2 patent portfolio includes the same patents and patent applications discussed above with respect to REG1.

Trade Secrets

In addition to patents, we rely on trade secrets and know-how to develop and maintain our competitive position. For example, significant aspects of our proprietary technology platform are based on
unpatented trade secrets and know-how. Trade secrets and know-how can be difficult to protect. We seek to protect our proprietary technology and processes, in part, by confidentiality agreements and invention assignment agreements with our
employees, consultants, scientific advisors, contractors and commercial partners. These agreements are designed to protect our proprietary information and, in the case of the invention assignment agreements, to grant us ownership of technologies
that are developed through a relationship with a third party. We also seek to preserve the integrity and confidentiality of our data and trade secrets by maintaining physical security of our premises and physical and electronic security of our
information technology systems. While we have confidence in these individuals, organizations and systems, agreements or security measures may be breached, and we may not have adequate remedies for any breach. In addition, our trade secrets may
otherwise become known or be independently discovered by competitors. To the extent that our contractors use intellectual property owned by others in their work for us, disputes may arise as to the rights in related or resulting know-how and
inventions.

Trademarks

We seek trademark protection in the United States and outside of the United States where available and when appropriate. We have registered trademark rights in the TAKING SCIENCE TO HEART mark in the
United States and Israel, to the WE TAKE SCIENCE TO HEART mark in the United States, to the REGADO BIOSCIENCES mark in the United States, Canada and Israel, and to the REGADO mark in the United States and Israel. We have registered trademark rights
in REGADO BIOSCIENCES THE ACTIVE CONTROL AGENT CONTROL COMPANY in Israel. We use these registered marks in connection with our pharmaceutical research and development as well as our product candidates.

License Agreements

Duke License Agreement

We entered into a license agreement with Duke in November 2004, which was amended in July 2005. Under the amended agreement, we obtained an exclusive worldwide license to make, have made, use, lease,
offer for sale, sell, distribute and export license products, including the right to sublicense, under certain Duke patent rights relating to aptamers with an active control agent and to genus claims to anti-FIXa aptamers and a non-exclusive license
to related Duke know-how. Duke retains the right to practice the patent rights licensed under

the agreement for its educational, research, publication and clinical purposes, and to provide materials covered by such patent rights to certain third parties for non-commercial purposes.

We issued 11,452 shares of our common stock to Duke as consideration for the license agreement. In addition, we may be
required to pay to Duke an aggregate of $1.75 million per product upon the achievement of specified development and regulatory approval milestones, including $500,000 payable upon the commencement of the REGULATE-PCI trial. Through March 31, 2013,
no milestone payments had been made under this license agreement. All of our product candidates are subject to the terms of the Duke license.

We also are required to pay Duke royalties based on a percentage of net sales for products and services sold by us or our sublicensees that utilize, incorporate or practice any of the licensed patent
rights. The percentage royalty rate is in the low single digits. These royalties may be reduced if we are required to obtain a third-party license to practice the Duke patent rights.

The agreement requires us to use reasonable best efforts to commercialize products and services based on the licensed technology and to
continue active and diligent marketing efforts of any commercialized products and services for the life of the agreement.

We
may terminate the agreement at any time upon three months written notice. Either party may terminate the agreement upon a judgment or conviction holding that the other party has committed fraud, willful misconduct or illegal conduct with respect to
the subject matter of the agreement or upon a material breach of the agreement by the other party, subject to the breaching partys limited right to avoid termination by curing the material breach in certain circumstances. Absent any early
termination, the term of the agreement continues until the last of the licensed patent rights has expired or become abandoned. The longest lived patent rights licensed to us under the agreement are expected to expire in 2023 as a result of patent
term adjustments.

Archemix License Agreement

In October 2003, we entered into a license agreement with Archemix pursuant to which we obtained an exclusive worldwide license to
develop, manufacture, use, sell, offer for sale, have sold and import licensed products under certain patent rights and know-how owned or controlled by Archemix for products that contain an aptamer and active control agent for use in the treatment
of diseases or conditions in humans caused or characterized by factors involved in, and the modulation of, fibrin deposition, platelet adhesion and/or platelet aggregation. The agreement excludes conditions or diseases of the eye, the orbit and its
contents, the eyelids or the lachrymal system, as well as the diagnosis of any diseases or conditions and any uses relating to the handling or storage of blood or blood products.

Under the agreement, we also obtained a non-exclusive research license to the SELEX process for identifying and developing aptamers for use solely as part of the licensed products described above.

The agreement provides for a non-exclusive license back to Archemix to use and sublicense our
improvements related to the SELEX process, as well as a nonexclusive license to use, for internal research
solely within Archemix, other improvements we make to the intellectual property licensed from Archemix.

We issued 6,736 shares
of our common stock to Archemix as consideration for the license agreement. In addition, we may be required to pay to Archemix an aggregate of $5.5 million upon the achievement of specified development and regulatory approval milestones, including
$1.0 million upon the commencement of the REGULATE-PCI trial. Through March 31, 2013, no milestone payments had been made under this license agreement. All of our product candidates are subject to the terms of the Archemix license.

We also are required to pay Archemix royalties based on the net sales of licensed products by us and our affiliates. The
royalty rate is in the mid-single digits. The longest lived patent rights licensed to us under the agreement are expected to expire in 2017.

To the extent that any intellectual property that we license from Archemix, other than intellectual property relating to the SELEX process, is held by a third party licensor of Archemix, we may be responsible for paying incremental costs that Archemix is required to pay to such third-party
licensor on account of the license Archemix has granted to us.

The agreement requires us to use commercially reasonable efforts to proceed with the
development, manufacture and sale of licensed products. We may enter into collaboration agreements with third parties with respect to part or all of the development or commercialization of one or more licensed products, subject to Archemixs
right of first refusal with respect to any such proposed collaboration agreement in certain limited circumstances. We also have the right to grant sublicenses to the intellectual property licensed from Archemix subject to the obligation to pay
Archemix royalties based on amounts received pursuant to any such sublicenses.

We may terminate the agreement at any time upon
60 days written notice. Either party may terminate the agreement if the other party commits a material breach of the agreement and fails to cure the breach within 60 days after written notice. Absent any early termination, the term of the
agreement continues until the last valid claim within the licensed patent rights expires. The agreement provides that upon expiration, we will have a paid up, exclusive, worldwide licensed under the know-how rights licensed from Archemix in the
field licensed to us under the agreement.

Nektar License and Supply Agreement

In December 2006, we entered into a license, manufacturing and supply agreement with Nektar pursuant to which we obtained an exclusive,
worldwide license to certain Nektar-controlled patent rights and know-how pertaining to the PEG and other pegylation technology used for pegnivacogin, solely to make, have made, import, use, offer for sale, sell and otherwise exploit pegnivacogin
for the treatment, prevention or diagnosis of human diseases or conditions, other than Hemophilia A. Nektar retains the right to practice the licensed patent rights and know-how for research and development of products that it is developing itself
or with others and to perform obligations to third parties set forth in agreements existing as of the effective date of our agreement.

We have the right to grant sublicenses to third parties, provided that any sublicensee of the Nektar-controlled patent rights and know-how at the time is not a competitor of Nektar.

We may be required to pay to Nektar an aggregate of $7.75 million upon the achievement of specified development and regulatory approval
milestones. Through March 31, 2013, we made payments under this license agreement totaling $1.25 million.

We also are required
to pay Nektar royalties based on a percentage of net sales of our REG1 product by us or our sublicensees. The percentage royalty rates are in the mid-single digits, and are subject to reduction with respect to sales in a country if none of the
patents and patent applications that we license under the agreement cover REG1 or the PEG in such country. These royalties also may be reduced if we are required to pay royalties to a third party due to infringement relating to the PEG. The duration
of our royalty obligation expires on a country-by-country basis on the later of ten years after first commercial sale of REG1 in a country and the expiration of the last-to-expire of the licensed patent rights in such country.

If we enter into a transaction where we grant a third party any rights to distribute, promote, market or sell REG1, or we sublicense any
of the rights licensed to us under the agreement, then we are required to pay Nektar a specified percentage of the first payment we receive in such transaction, up to a specified maximum payment to Nektar.

We are required to purchase 100% of our and our sublicensees requirements of the PEG for the REG1 product from Nektar, at a purchase
price defined in the agreement, which purchase price is subject to annual increases based on inflation index changes.

We may
terminate the agreement at any time upon 60 days written notice, subject to our obligation to pay an early termination fee to Nektar. Our right to terminate the agreement early is further subject to our obligation to continue to make certain
minimum purchases from Nektar of the PEG and to continue to pay Nektar royalties for net sales of REG1 that incorporates such PEG purchased from Nektar. Either party may terminate the agreement if the other party fails to comply with the material
terms of the agreement and does not correct such failure within 30 days for failures to make timely payment or 90 days for other failures. Nektar also may terminate the agreement if we or a sublicensee challenges the validity, scope or
enforceability of or otherwise opposes any of the patent rights licensed to us under the agreement. Absent any early termination, the term of the agreement continues until all royalty obligations under the agreement expire.

In connection with our Series E Preferred Stock financing, in December 2012, we entered into a Technology Transfer Agreement, or the Tech Transfer Agreement, with Domain Russia Investments Limited, or
DRI, an affiliate of Domain Partners VIII, L.P. Domain Partners VIII, L.P. and Domain Partners VI, L.P., a significant stockholder of our company, are both managed by Domain Associates, L.L.C. Pursuant to the Tech Transfer Agreement, in exchange for
a nominal payment, we assigned to DRI certain patents and patents applications in Armenia, Azerbaijan, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Moldova, Russia, Tajikistan, Turkmenistan, Ukraine and Uzbekistan, or the Covered Territory, and granted
to DRI an exclusive, fully paid-up, royalty-free, irrevocable and assignable license under our non-patent intellectual property to develop and commercialize REG1 and our other product candidates in the Covered Territory. Immediately thereafter, we,
together with DRI and NovaMedica, LLC, or NovaMedica, executed an Assignment and Assumption Agreement, pursuant to which all of DRIs rights and obligations under the Tech Transfer Agreement were transferred to NovaMedica. DRI also has a right
of first negotiation if we desire to partner with a third party to develop or commercialize future product candidates in the Covered Territory, which was assigned to NovaMedica. We agreed to take all action required to register or record the patent
transfers to DRI in each country in the Covered Territory and to ensure the assignment of DRIs rights under the Tech Transfer Agreement to NovaMedica. NovaMedica is jointly owned by Rusnano Medinvest LLC, or Rusnano Medinvest, and DRI. RMI
Investments, S.á.r.l, or RMII, a significant stockholder of ours, is a wholly-owned subsidiary of Rusnano Medinvest. In connection with the second tranche closing of our Series E Preferred Stock financing, we agreed to file certain patent
transfer applications and to take certain other related actions which have been completed. See Certain Relationships and Related Party Transactions  Series E Financing.

Under the terms of the Tech Transfer Agreement, upon request we have agreed to provide certain development support to NovaMedica and to
use commercially reasonable efforts to assist NovaMedica to establish a manufacturing relationship with our CMOs. We also have agreed to provide NovaMedica with certain manufacturing know-how and support, including making our manufacturing employees
available to provide scientific and technical explanations, advice and on-site support that may be reasonably requested by NovaMedica. NovaMedica is required to reimburse us for any out-of-pocket expenses incurred by us in providing this assistance,
including travel-related expenses. We estimate that the aggregate out-of-pocket expense of providing such services will be approximately $250,000. In addition, prior to the first commercial sale of a product candidate, we have agreed to sell to
NovaMedica sufficient quantities of each product candidate and related compounds to enable NovaMedica to conduct clinical trials of such product candidate in the Covered Territory at cost plus a mark-up in the low double digits so long as any sale
does not reasonably interfere with our own development and commercialization activities.

Concurrently with the signing of the
Tech Transfer Agreement, we also entered into a letter agreement with DRI pursuant to which we are obligated to pay DRI a make-whole payment up to a maximum amount of $1.2 million in the event that an independent appraisers valuation of
certain patent applications assigned to DRI under the Tech Transfer Agreement is less than $1.2 million. The letter agreement provides that such payment will be refunded to us if DRI receives certain capital contribution credits with respect to such
patent applications in connection with its investment in NovaMedica. DRI has advised us that the independent appraiser valued the assigned patent applications at more than $1.2 million. As a result, DRI is not entitled to any make-whole payment
under the terms of the letter agreement. In addition, we have agreed to indemnify DRI against any claims brought by NovaMedica arising out of or resulting from any breach of specified representations and warranties which we made in the Tech Transfer
Agreement up to a maximum amount of $1.2 million, less any payments made to DRI in connection with the valuation of the assigned intellectual property. Our indemnification obligation will expire two years following the first commercial sale of REG1
or our other product candidates in the Covered Territory or six years after the date of the letter agreement if no such commercial sales have occurred.

The Tech Transfer Agreement also provides that we will enter into a Clinical Development and Collaboration Agreement, a Supply Agreement and certain related agreements with NovaMedica to implement the
terms of the Tech Transfer Agreement. In connection with the second tranche of the initial closing of our Series E Preferred Stock financing, we agreed to use commercially reasonably efforts to negotiate, execute and

deliver the Clinical Development and Collaboration Agreement on or before May 31, 2013. See Certain Relationships Related Party TransactionsSeries E Financing. The Tech Transfer
Agreement provides that the Supply Agreement will cover the commercial supply of product candidates and related drug compounds to NovaMedica at cost plus a mark-up in the low double digits.

In accordance with the terms of the Tech Transfer Agreement, in May 2013 we entered into a Clinical Development and Collaboration
Agreement, or the Collaboration Agreement, with NovaMedica pursuant to which we agreed to assist NovaMedica in the development and commercialization of our product candidates in the Covered Territory. The Collaboration Agreement requires the
formation of several committees consisting of our representatives and NovaMedica representatives to oversee the general development, day-to-day development work and commercialization of our product candidates for the intended field of use in the
Covered Territory. All decisions of these committees must be made by unanimous vote, subject to a dispute resolution process. Under the terms of the Collaboration Agreement, the joint committees will determine a development plan for REG1 for its
initial indication and any additional significant commercial indications for REG1, as well as for additional product candidates. NovaMedica will have sole responsibility for the costs and expenses of obtaining regulatory approval for our product
candidates and for commercializing any approved products in the Covered Territory and will have the right to conduct its own clinical studies in the Covered Territory at its sole expense. NovaMedica also has the right to file applications for
approval of our product candidates in the Covered Territory, subject to committee oversight. We have agreed, among other things, to provide NovaMedica with clinical data necessary for it to obtain necessary approvals in the Covered Territory,
information relating to applications for regulatory approval of our product candidates, certain commercialization information and to assist NovaMedica in conducting any clinical trials necessary for regulatory approval of our product candidates in
the Covered Territory. We also have agreed to provide NovaMedica with certain development know-how and support, including making our clinical development personnel available to provide scientific and technical explanations, advice and on-site
support that may be reasonably requested by NovaMedica.

NovaMedica is required to reimburse us for any out-of-pocket expenses
incurred by us in providing this assistance, including travel-related expenses. We estimate that the aggregate out-of-pocket expense of providing such services will be approximately $500,000. Pursuant to the Collaboration Agreement, we have agreed
to use commercially reasonable efforts to include sites in the Covered Territory in our clinical trial programs for our product candidates at our sole expense. Under the Collaboration Agreement, prior to the first commercial sale of a product
candidate in the Covered Territory, NovaMedica will have the right to purchase product candidates and related compounds from us or through us as are reasonable and necessary for it to conduct clinical trials in the Covered Territory at our cost plus
a mark-up in the low double digits pursuant to a clinical supply agreement to be entered into within 120 days of the date of the Collaboration Agreement. NovaMedica has agreed to supervise and maintain sales representatives for the commercialization
of any product candidates approved for sale in the Covered Territory. Within 90 days of receipt of FDA approval for the use of any product candidate, we are obligated to enter into a commercial supply agreement with NovaMedica for the supply of such
candidate on terms to be negotiated by the parties. In the Collaboration Agreement, the parties also agreed to customary terms and conditions, including the ownership and use of intellectual property, rights to information, prosecution of patent
rights, rights under third-party agreements, confidentiality and indemnification obligations and mechanisms for the resolution of disputes. The Collaboration Agreement expires on the earlier of three years following the first commercial sale of a
product candidate in the Covered Territory or nine years from the date of effectiveness and terminates upon the termination of the Tech Transfer Agreement. NovaMedica also has the right to terminate the Collaboration Agreement at any time at its
convenience upon 90 days prior written notice.

Sales and Marketing

Because REG1 is a hospital-based acute care product, we believe that it is feasible for us to commercialize REG1 with a relatively small
specialty sales force calling on a targeted group of hospital-based interventional cardiologists. If REG1 is approved, our current plan is to commercialize REG1 in the United States by building a commercial infrastructure or utilizing contract
reimbursement specialists, sales people and medical education specialists. We may seek to augment our commercial efforts by entering into a collaboration with a

pharmaceutical company, if such a collaboration is available on attractive terms. Outside of the United States, we likely will seek to commercialize REG1 through distribution or other
collaboration arrangements.

Competition

The biopharmaceutical industry is characterized by intense competition and rapid innovation. Our potential competitors include large pharmaceutical and biotechnology companies, specialty pharmaceutical
companies and generic drug companies. We believe the key competitive factors that will affect the development and commercial success of our product candidates are efficacy, safety and tolerability profile, mechanism of action, control and
predictability, convenience of dosing and price and reimbursement.

Our most advanced product candidate,
REG1, is being developed for use in patients undergoing PCI for a wide variety of cardiovascular conditions. If approved for this indication, REG1 would compete with a number of currently-marketed anticoagulants, including bivalirudin, currently
marketed and sold by The Medicines Company under the brand name Angiomax® in the United States, and UFH and
LMWH, both of which are available as biosimilars and which are currently manufactured and sold by a number of companies. Otamixaban, which is being developed by Sanofi, is being evaluated in a Phase 3 clinical trial for patients with UA or N-STEMI
scheduled to undergo an early invasive strategy.

We intend to develop REG1 for use in additional cardiovascular procedures,
such as OHS, PCI as a treatment for STEMI, and TAVI. If approved for these indications, REG1 would compete primarily with UFH and LMWH.

We believe that our product candidates offer key potential advantages over these competitive products that could enable our product candidates, if approved, to capture meaningful market share from our
competitors. However, many of our potential competitors have substantially greater financial, technical and human resources than we do, as well as greater experience in the discovery and development of product candidates, obtaining FDA and other
regulatory approvals of products and the commercialization of those products. Accordingly, our competitors may be more successful than us in obtaining regulatory approval for drugs and achieving widespread market acceptance. Our competitors
drugs may be more effective, or more effectively marketed and sold, than any product candidate we may commercialize and may render our product candidates obsolete or non-competitive before we can recover the expenses of their development and
commercialization. We anticipate that we will face intense and increasing competition as new drugs enter the market and advanced technologies become available. Finally, the development of new treatment methods for the diseases we are targeting could
render our product candidates non-competitive or obsolete.

Government Regulation and Product Approval

Government authorities in the United States at the federal, state and local level extensively regulate, among other things, the research,
development, testing, manufacture, quality control, approval, labeling, packaging, storage, record-keeping, promotion, advertising, distribution, marketing, export and import of products such as those we are developing. Our product candidates must
receive final approval from the FDA before they may legally be marketed in the United States.

U.S. Drug Development
Process

In the United States, the FDA regulates drugs under the Federal Food, Drug, and Cosmetic Act, or FDCA, and
implementing regulations. The process of obtaining regulatory approvals and ensuring compliance with appropriate federal, state, local and foreign statutes and regulations requires the expenditure of substantial time and financial resources. Failure
to comply with the applicable U.S. requirements at any time during the product development process, approval process, or after approval, may subject an applicant to administrative or judicial sanctions. These sanctions could include the FDAs
refusal to approve pending applications, withdrawal of an approval, a clinical hold, warning letters, product seizures, product detention, total or partial suspension of production or distribution, injunctions, fines, refusals of government
contracts, restitution, disgorgement or civil or criminal penalties. The process required by the FDA before a drug may be marketed in the United States generally involves the following:



completion of preclinical laboratory tests and animal studies according to Good Laboratory Practices or other regulations, as well as formulation
studies;

submission to the FDA of an investigational new drug application, or IND, which must become effective before human clinical trials may begin;



performance of adequate and well-controlled human clinical trials according to Good Clinical Practices, or GCP, to establish the safety and efficacy of
the proposed drug for its intended use;

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submission to the FDA of an NDA for a new drug;

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satisfactory completion of an FDA inspection of the manufacturing facility or facilities at which the drug is produced to assess compliance with
current Good Manufacturing Practices, or cGMP, to assure that the facilities, methods and controls are adequate to preserve the drugs identity, strength, quality and purity; and



FDA review and approval of the NDA.

The testing and approval process require substantial time, effort and financial resources and we cannot be certain that any approvals for our product candidates will be granted on a timely basis, if at
all.

Once a pharmaceutical product candidate is identified for development, it enters the preclinical testing stage. The
preclinical testing stage includes laboratory evaluations of product chemistry, toxicity, formulation and stability, as well as animal studies. An IND sponsor must submit the results of the preclinical tests, together with manufacturing information,
analytical data and any available clinical data or literature, to the FDA as part of the IND. The sponsor must also include a protocol detailing, among other things, the objectives of the initial clinical trial, the parameters to be used in
monitoring safety and the effectiveness criteria to be evaluated if the initial clinical trial lends itself to an efficacy evaluation. Preclinical testing may continue even after the IND is submitted. The IND automatically becomes effective 30 days
after receipt by the FDA, unless the FDA places the clinical trial on a clinical hold within that 30-day time period. In such a case, the IND sponsor and the FDA must resolve any outstanding concerns before the clinical trial can begin. Clinical
holds also may be imposed by the FDA at any time before or during trials due to safety concerns or non-compliance.

All
clinical trials must be conducted under the supervision of one or more qualified investigators in accordance with GCP regulations. These regulations include the requirement that all research subjects provide informed consent. Further, an
institutional review board, or IRB, must review and approve the plan for any clinical trial before it commences at any institution. An IRB considers, among other things, whether the risks to individuals participating in the trials are minimized and
are reasonable in relation to anticipated benefits. The IRB also approves the information regarding the clinical trial and the consent form that must be provided to each clinical trial subject or his or her legal representative and must monitor the
clinical trial until completed. Once an IND is in effect, each new clinical protocol and any amendments to the protocol must be submitted to the IND for FDA review, and to the IRBs for approval.

Human clinical trials are typically conducted in three sequential phases that may overlap or be combined:

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Phase 1. The product candidate is initially introduced into healthy human subjects and tested for tolerance, absorption, metabolism,
distribution and excretion. In the case of some products for severe or life-threatening diseases, especially when the product may be too inherently toxic to ethically administer to healthy volunteers, the initial human testing may be conducted in
patients having the specific disease.



Phase 2. Phase 2 trials involve investigations in a limited patient population to identify possible adverse effects and safety risks, to
preliminarily evaluate the efficacy of the product candidate for specific targeted diseases and to determine optimal dosage and schedule.



Phase 3. Clinical trials are undertaken to further evaluate dosage, clinical efficacy and safety in a larger patient population at
geographically dispersed clinical trial sites. These trials are intended to establish the overall risk/benefit ratio of the product candidate and provide an adequate basis for regulatory approval and product labeling.

Post-approval studies, also called Phase 4 trials, may be conducted after initial marketing approvals. These studies are used to obtain
additional experience from the treatment of patients in the intended therapeutic indication and may be required by the FDA as part of the approval process.

Progress reports detailing the results of the clinical trials must be submitted annually to
the FDA and safety reports must be submitted to the FDA and the investigators for serious and unexpected side effects. Phase 1, Phase 2 and Phase 3 testing may not be completed successfully within any specified period, if at all. The FDA or the
sponsor may suspend or terminate a clinical trial at any time on various grounds, including a finding that the research subjects or patients are being exposed to an unacceptable health risk. Similarly, an IRB can suspend or terminate approval of a
clinical trial at its institution if the clinical trial is not being conducted in accordance with the IRBs requirements or if the drug has been associated with unexpected serious harm to patients.

Concurrent with clinical trials, companies usually complete additional animal studies and must also develop additional information about
the chemistry and physical characteristics of the product and finalize a process for manufacturing the product in commercial quantities in accordance with cGMP requirements. The manufacturing process must be capable of consistently producing quality
batches of the product candidate and, among other things, the manufacturer must develop methods for testing the identity, strength, quality and purity of the final product. Additionally, appropriate packaging must be selected and tested and
stability studies must be conducted to demonstrate that the product candidate does not undergo unacceptable deterioration over its shelf life.

United States Review and Approval Processes

The results of product
development, preclinical studies and clinical trials, along with descriptions of the manufacturing process, analytical tests conducted on the drug, proposed labeling and other relevant information, are submitted to the FDA as part of an NDA,
requesting approval to market the product. The submission of an NDA is subject to the payment of substantial user fees which may be waived under certain limited circumstances.

FDA Review of New Drug Applications

The FDA reviews all NDAs submitted to
ensure that they are sufficiently complete for substantive review before it accepts them for filing. The FDA may request additional information rather than accept an NDA for filing. In this event, the NDA must be re-submitted with the additional
information. The re-submitted application also is subject to review before the FDA accepts it for filing. Once the submission is accepted for filing, the FDA begins an in-depth substantive review. Under the goals and policies agreed to by the FDA
under the Prescription Drug User Fee Act, or PDUFA, the FDA has ten months in which to complete the initial review of a standard NDA and respond to the applicant and six months for a priority NDA. The FDA does not always meet its PDUFA goal dates
for standard and priority NDAs. The FDA reviews an NDA to determine, among other things, whether a product is safe and effective for its intended use and whether the chemistry, manufacturing and control documentation is adequate to assure and
preserve the products identity, strength, quality and purity. Before approving an NDA, the FDA will inspect the facility or facilities where the product is manufactured. The FDA will not approve an application unless it determines that the
manufacturing processes and facilities are in compliance with cGMP requirements and adequate to assure consistent production of the product within required specifications. The FDA may refer the NDA to an advisory committee for review, evaluation and
recommendation as to whether the application should be approved and under what conditions. An advisory committee is a panel of independent experts who provide advice and recommendations when requested by the FDA on matters of importance that come
before the agency. The FDA is not bound by the recommendation of an advisory committee.

The approval process is lengthy and
difficult and the FDA may refuse to approve an NDA if the applicable regulatory criteria are not satisfied or may require additional clinical data or other data and information.

Even if such data and information is submitted, the FDA may ultimately decide that the NDA does not satisfy the criteria for approval.
Data obtained from clinical trials are not always conclusive and the FDA may interpret data differently than we interpret the same data. The FDA will issue a complete response letter if the agency decides not to approve the NDA in its present form.
The complete response letter usually describes all of the specific deficiencies that the FDA identified in the NDA. The deficiencies identified may be minor, for example, requiring labeling changes, or major, for example, requiring additional
clinical trials. Additionally, the complete response letter may include recommended actions that the applicant might take to conform the application to a condition suitable for approval. If a complete response letter is issued, the applicant may
either resubmit the NDA, addressing all of the deficiencies identified in the letter, withdraw the application, or request an opportunity for a hearing.

If a product receives regulatory approval, the approval may be significantly limited to
specific diseases and dosages or the indications for use may otherwise be limited, which could restrict the commercial value of the product. Further, the FDA may require that certain contraindications, warnings or precautions be included in the
product labeling. In addition, the FDA may require Phase 4 testing which involves clinical trials designed to further assess a drugs safety and effectiveness after NDA approval and may require testing and surveillance programs to monitor the
safety of approved products that have been commercialized.

Patent Term Restoration and Marketing Exclusivity

Depending upon the timing, duration and specifics of FDA marketing approval of our product candidates, some of our U.S.
patents may be eligible for limited patent term extension under the Drug Price Competition and Patent Term Restoration Act of 1984, commonly referred to as the Hatch-Waxman Amendments. The Hatch-Waxman Amendments permit a patent restoration term of
up to five years as compensation for patent term lost during product development and the FDA regulatory review process. However, patent term restoration cannot extend the remaining term of a patent beyond a total of 14 years from the products
approval date. The patent term restoration period is generally one-half the time between (a) the effective date of an IND and the submission date of an NDA plus (b) the time between the submission date of an NDA and the approval of that
application. Only one patent applicable to an approved drug is eligible for the extension and the application for the extension must be submitted prior to the expiration of the patent and within 60 days of approval of the drug. The PTO, in
consultation with the FDA, reviews and approves the application for any patent term extension or restoration.

Market
exclusivity provisions under the FDCA can also delay the submission or the approval of certain applications. The FDCA provides a five-year period of non-patent marketing exclusivity within the United States to the first applicant to gain approval of
an NDA for a new chemical entity. A drug is a new chemical entity if the FDA has not previously approved any other new drug containing the same active pharmaceutical ingredient, or active moiety, which is the molecule or ion responsible for the
action of the drug substance. During the exclusivity period, the FDA may not accept for review an abbreviated new drug application, or ANDA, or a Section 505(b)(2) NDA submitted by another company for another version of such drug where the
applicant does not own or have a legal right of reference to all the data required for approval. Section 505(b)(2) permits the submission of an NDA where at least some of the information required for approval comes from clinical trials not
conducted by or for the applicant and for which the applicant has not obtained a right of reference. However, the FDCA will not prevent the submission or approval of another full Section 505(b)(1) NDA, but such an NDA applicant would be
required to conduct its own preclinical and adequate, well-controlled clinical trials to demonstrate safety and effectiveness. Further, a Section 505(b)(2) application may be submitted after four years if it contains a Paragraph IV
certification claiming that the patents covering the drug are either invalid or not infringed by the drug described in the 505(b)(2) application. The FDCA also provides three years of marketing exclusivity for an NDA, Section 505(b)(2) NDA or
supplement to an existing NDA if new clinical investigations, other than bioavailability studies, that were conducted or sponsored by the applicant are deemed by the FDA to be essential to the approval of the application. Such clinical trials may,
for example, support new indications, dosages, routes of administration or strengths of an existing drug, or for a new use, if new clinical investigations that were conducted or sponsored by the applicant are determined by the FDA to be essential to
the approval of the application. This exclusivity, which is sometimes referred to as clinical investigation exclusivity, prevents the FDA from approving an application under Section 505(b)(2) for the same conditions of use associated with the
new clinical investigations before the expiration of three years from the date of approval. Such three-year exclusivity, however, would not prevent the approval of another application if the applicant submits a Section 505(b)(1) NDA and has
conducted its own adequate, well-controlled clinical trials demonstrating safety and efficacy, nor would it prevent approval of a generic product or Section 505(b)(2) product that did not incorporate the exclusivity-protected changes of the
approved drug product. The FDCA, FDA regulations and other applicable regulations and policies provide incentives to manufacturers to create modified, non-infringing versions of a drug to facilitate the approval of an ANDA or other application for
generic substitutes.

Any drugs for which we receive FDA approval are subject to continuing regulation by the FDA, including, among other things, record-keeping
requirements, reporting of adverse effects with the product, providing the FDA with updated safety and efficacy information, product sampling and distribution requirements, complying with certain electronic records and signature requirements and
complying with FDA promotion and advertising requirements. In September 2007, the Food and Drug Administration Amendments Act of 2007 was enacted, giving the FDA enhanced post-marketing authority, including the authority to require post-marketing
studies and clinical trials, labeling changes based on new safety information, and compliance with risk evaluations and mitigation strategies approved by the FDA. The FDA strictly regulates labeling, advertising, promotion and other types of
information on products that are placed on the market. Drugs may be promoted only for the approved indications and in accordance with the provisions of the approved label. Further, manufacturers of drugs must continue to comply with cGMP
requirements, which are extensive and require considerable time, resources and ongoing investment to ensure compliance. In addition, certain changes to the manufacturing process generally require prior FDA approval before being implemented and other
types of changes to the approved product, such as adding new indications and additional labeling claims, are also subject to further FDA review and approval.

Drug manufacturers and other entities involved in the manufacturing and distribution of approved drugs are required to register their establishments with the FDA and certain state agencies, and are
subject to periodic unannounced inspections by the FDA and certain state agencies for compliance with cGMP and other laws. The cGMP requirements apply to all stages of the manufacturing process, including the production, processing, sterilization,
packaging, labeling, storage and shipment of the drug. Manufacturers must establish validated systems to ensure that products meet specifications and regulatory standards, and test each product batch or lot prior to its release.

The FDA may restrict market availability or withdraw a product approval if compliance with regulatory standards is not maintained or if
problems occur after the product reaches the market. Discovery of previously unknown problems with a product subsequent to its approval may result in restrictions on the product or even complete withdrawal of the product from the market. Further,
the failure to maintain compliance with regulatory requirements may result in administrative or judicial actions, such as fines, warning letters, holds on clinical trials, product seizures, product detention or refusal to permit the import or export
of products, refusal to approve pending applications or supplements, restrictions on marketing or manufacturing, injunctions or civil or criminal penalties.

From time to time, legislation is drafted, introduced and passed in Congress that could significantly change the statutory provisions governing the approval, manufacturing and marketing of products
regulated by the FDA. For example, in July 2012, the Food and Drug Administration Safety and Innovation Act was enacted, expanding drug supply chain requirements and strengthening FDAs response to drug shortages, among other things. In
addition to new legislation, the FDA regulations and policies are often revised or reinterpreted by the agency in ways that may significantly affect our business and our product candidates. It is impossible to predict whether further legislative or
FDA regulation or policy changes will be enacted or implemented and what the impact of such changes, if any, may be.

Foreign Regulation

In addition to regulations in the United States, we will be subject to a variety of foreign regulations governing clinical trials and commercial sales and distribution of our product candidates to the
extent we choose to clinically evaluate or sell any products outside of the United States. Whether or not we obtain FDA approval for a product, we must obtain approval of a product by the comparable regulatory authorities of foreign countries before
we can commence clinical trials or marketing of the product in those countries. The approval process varies from country to country and the time may be longer or shorter than that required for FDA approval. The requirements governing the conduct of
clinical trials, product licensing, pricing and reimbursement vary greatly from country to country. As in the United States, post-approval regulatory requirements, such as those regarding product manufacture, marketing, or distribution would apply
to any product that is approved outside the United States.

Significant uncertainty exists as to the coverage and reimbursement status of any of our drug candidates for which we obtain regulatory
approval. In both the United States and foreign markets, our ability to commercialize our product candidates successfully, and to attract commercialization partners for our product candidates, depends in significant part on the availability of
adequate financial coverage and reimbursement from third-party payors, including, in the United States, governmental payors such as the Medicare and Medicaid programs, managed care organizations, and private health insurers. Medicare is a federally
funded program managed by the Centers for Medicare and Medicaid Services, or CMS, through local fiscal intermediaries and carriers that administer coverage and reimbursement for certain healthcare items and services furnished to the elderly and
disabled. Medicaid is an insurance program for certain categories of patients whose income and assets fall below state defined levels and who are otherwise uninsured that is both federally and state funded and managed by each state. The federal
government sets general guidelines for Medicaid and each state creates specific regulations that govern its individual program. Each payor has its own process and standards for determining whether it will cover and reimburse a procedure or
particular product. Private payors often rely on the lead of the governmental payors in rendering coverage and reimbursement determinations. Therefore, achieving favorable CMS coverage and reimbursement is usually a significant gating issue for
successful introduction of a new product. The competitive position of some of our products will depend, in part, upon the extent of coverage and adequate reimbursement for such products and for the procedures in which such products are used. Prices
at which we or our customers seek reimbursement for our product candidates can be subject to challenge, reduction or denial by the government and other payors.

The U.S. Congress and state legislatures may, from time to time, propose and adopt initiatives aimed at cost containment, which could impact our ability to sell our product candidates profitably. For
example, in March 2010, President Obama signed into law the Patient Protection and Affordable Care Act and the associated reconciliation bill, which we refer to collectively as the Health Care Reform Law, a sweeping law intended to broaden access to
health insurance, reduce or constrain the growth of healthcare spending, enhance remedies against fraud and abuse, add new transparency requirements for healthcare and health insurance industries, impose new taxes and fees on the health industry and
impose additional health policy reforms. Effective October 1, 2010, the Health Care Reform Law revised the definition of average manufacturer price for reporting purposes, which could increase the amount of Medicaid drug rebates to
states once the provision is effective. Further, the law imposes a significant annual fee on companies that manufacture or import branded prescription drug products. Substantial new provisions affecting compliance have also been enacted, which may
require us to modify our business practices with healthcare practitioners. We will not know the full effects of the Health Care Reform Law until applicable federal and state agencies issue regulations or guidance under the new law. Although it is
too early to determine the effect of the Health Care Reform Law, the new law appears likely to continue the pressure on pharmaceutical pricing, especially under the Medicare program, and may also increase our regulatory burdens and operating costs.
Moreover, in the coming years, additional changes could be made to governmental healthcare programs that could significantly impact the success of our product candidates.

The cost of pharmaceuticals continues to generate substantial governmental and third-party payor interest. We expect that the pharmaceutical industry will experience pricing pressures due to the trend
toward managed healthcare, the increasing influence of managed care organizations and additional legislative proposals. Our results of operations could be adversely affected by current and future healthcare reforms.

Some third-party payors also require pre-approval of coverage for new or innovative devices or drug therapies before they will reimburse
healthcare providers that use such therapies. While we cannot predict whether any proposed cost-containment measures will be adopted or otherwise implemented in the future, the announcement or adoption of these proposals could have a material
adverse effect on our ability to obtain adequate prices for our product candidates and operate profitably.

Other
Healthcare Laws and Compliance Requirements

In the United States, our activities are potentially subject to regulation
by various federal, state and local authorities in addition to the FDA, including the CMS, other divisions of the United States Department of Health

and Human Services (e.g., the Office of Inspector General), the United States Department of Justice and individual United States Attorney offices within the Department of Justice, and state and
local governments. These regulations include:

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the federal healthcare program anti-kickback law which prohibits, among other things, persons from soliciting, receiving or providing remuneration,
directly or indirectly, to induce either the referral of an individual, for an item or service or the purchasing or ordering of a good or service, for which payment may be made under federal healthcare programs such as the Medicare and Medicaid
programs;

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federal false claims laws which prohibit, among other things, individuals or entities from knowingly presenting, or causing to be presented, claims for
payment from Medicare, Medicaid, or other government reimbursement programs that are false or fraudulent, and which may apply to entities like us which provide coding and billing advice to customers;

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the federal Health Insurance Portability and Accountability Act of 1996 which prohibits executing a scheme to defraud any healthcare benefit program or
making false statements relating to healthcare matters and which also imposes certain requirements relating to the privacy, security and transmission of individually identifiable health information;



the federal transparency requirements under the Health Care Reform Law requires manufacturers of drugs, devices, biologics, and medical supplies to
report to the Department of Health and Human Services information related to physician payments and other transfers of value and physician ownership and investment interests;

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the FDCA which, among other things, strictly regulates drug product marketing, prohibits manufacturers from marketing drug products for off-label use
and regulates the distribution of drug samples; and

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state law equivalents of each of the above federal laws, such as anti-kickback and false claims laws, which may apply to items or services reimbursed
by any third party payor, including commercial insurers, and state laws governing the privacy and security of health information in certain circumstances, many of which differ from each other in significant ways and often are not preempted by
federal laws, thus complicating compliance efforts.

Employees

As of April 29, 2013, we had a total of 29 full-time employees and one part-time employee. Twenty of our full-time employees hold graduate
degrees including ten doctorate degrees and 18 are engaged in full-time research and development activities. None of our employees are represented by a labor union and we consider our employee relations to be good. Of our 29 full-time employees, 16
work in North Carolina and 13 work in New Jersey.

Properties

Our corporate headquarters are located in Basking Ridge, New Jersey, where we lease 6,218 square feet of office space. In November 2008, we entered into a three-year lease agreement for that facility and
are currently on a month-to-month basis. We have a lab facility in Durham, North Carolina, where we lease 8,495 square feet of office space. In April 2007, we entered into a five-year lease agreement for that facility and are currently on a
month-to-month basis. In December 2012, we entered into a six-month lease for approximately 400 square feet of additional office space in Cary, North Carolina. In May 2013, we entered into a three-year lease agreement for 1,657 square feet of
administrative office space in Durham, North Carolina.

We believe that our existing facilities are adequate for our current
and expected future needs. We may seek to negotiate new leases or look for additional or alternate space for our operations. We believe that appropriate alternative space is readily available at similar rents.

Our executive officers are elected by, and serve at the discretion of, our board of directors. The business
experience for the past five years, and in some instances, for prior years, of each of our executive officers and directors is as follows:

David J. Mazzo, Ph.D. has served as our president and chief executive officer and as a member of our board of directors since August 2008. Dr. Mazzo has almost 30 years of experience in
the pharmaceutical industry. Most recently, from March 2007 to April 2008, he was president and chief executive officer of Æterna Zentaris, Inc., a publicly held Canadian biopharmaceutical company. From 2003 until 2007, Dr. Mazzo served
as president and chief executive officer of Chugai Pharma USA, LLC, a biopharmaceutical company which was the U.S. subsidiary of Chugai Pharmaceutical Co., Ltd. of Japan. Dr. Mazzo has also held senior management and executive positions in
research and development at Schering-Plough Corporation, a publicly held pharmaceutical company that was subsequently acquired by Merck & Co., Inc., Hoechst Marion Roussel, Inc., the US subsidiary of Hoechst AG, which was subsequently
acquired by Sanofi, a multinational pharmaceuticals company, and Rhone-Poulenc Rorer, Inc., a subsidiary of Rhone-Poulene SA, a French pharmaceuticals company, which was subsequently acquired by Hoechst AG. He currently serves on the boards of
directors of pSivida Corp., a publicly held biotechnology company, in the role of non-executive chairman, and Avanir Pharmaceuticals, Inc., a publicly held biopharmaceutical company. Dr. Mazzo earned a B.A. in the Honors Program
(Interdisciplinary Humanities) and a B.S. in Chemistry from Villanova University. In addition, Dr. Mazzo received his M.S. in

chemistry and his Ph.D. degree in analytical chemistry from the University of Massachusetts, Amherst. He was also a research fellow at the Ecole Polytechnique Federale de Lausanne, Switzerland.
We believe Dr. Mazzo possesses specific attributes that qualify him to serve as a member of our board of directors, including his insight and experience as our chief executive officer, which brings historic knowledge, operational expertise and
continuity to our board of directors, his experience as chief executive officer and in other senior management roles at other pharmaceutical and biotechnology companies and his service on other boards of directors in the biopharmaceutical industry.

Christopher E. Courts, CPA has served as our vice president, finance since April 2006. From 1997 to 2006,
Mr. Courts served as a finance director with ITC DeltaCom, Inc., a publicly held integrated communications provider, which was subsequently acquired by EarthLink, Inc., where his responsibilities included corporate budgeting, cost operations
and compliance with the Sarbanes-Oxley Act of 2002, as well as significant corporate transactions, including and culminating with the merger of Business Telecom, Inc. and ITC DeltaCom, Inc. in 2003. Mr. Courts is licensed as a Certified Public
Accountant in North Carolina, and he holds a B.A. in Finance and M.B.A. from Marshall University.

Steven L. Zelenkofske,
D.O., F.A.C.C. has served as our senior vice president, clinical and medical affairs and chief medical officer since January 2009. Dr. Zelenkofske has extensive experience as a principal investigator on a number of important trials in
cardiovascular medicine. From June 2007 until January 2009, Dr. Zelenkofske served as vice president, cardiovascular/thrombosis medical unit at Sanofi-Aventis Pharmaceutical, a U.S. subsidiary of Sanofi, a multinational pharmaceutical company,
and, from 2006 until 2007, as vice president of clinical sciences and chief patient safety officer for Boston Scientific Corporations cardiac rhythm management group. From 2002 to 2006, he was a senior director with Novartis AG, a publicly
held multinational healthcare company, where he held positions of increasing responsibility within its cardiovascular division, most recently serving as senior medical director, U.S. clinical development, hypertension and cardiovascular section
head. Dr. Zelenkofske is a practicing electrophysiologist at Lehigh Valley Hospital in Allentown, Pennsylvania, and serves as an associate professor of medicine at the College of Medicine of the Pennsylvania State University/Hershey Medical
Center and for the Philadelphia College of Osteopathic Medicine. He earned a B.S. and M.Sc. in biochemistry and immunopharmacology at Emory University. He holds a D.O. from the Philadelphia College of Osteopathic Medicine and has certifications in
clinical cardiac electrophysiology, cardiology and internal medicine, including a fellow of American Cardiology College.

Ellen McDonald has served as our senior vice president of business operations and chief business officer since January 2009. Ms. McDonald has nearly 20 years of experience in the
biopharmaceutical industry. From 2007 to April 2008, she served as chief business officer and senior vice president at Æterna Zentaris, Inc., a publicly held Canadian biopharmaceutical company. From 2005 to 2007, she served as senior vice
president, business operations, at Chugai Pharma USA, LLC, a biopharmaceutical company which was the U.S. subsidiary of Chugai Pharmaceutical Co., Ltd. of Japan. Prior to 2004, Ms. McDonald served as senior vice president, cardiovascular
marketing and medical at Bristol-Myers Squibb Company, a publicly held biopharmaceutical company, and served as vice president, oncology at Ortho Biotech, Inc., a Johnson & Johnson company. She earned a B.S. in General Engineering at the
United States Military Academy, West Point, following which she served for five years as an officer in the U.S. Army. She also earned an M.B.A. in the Executive Program at Columbia University.

Alexander R. Giaquinto, Ph.D. has served as our as senior vice president of regulatory affairs and quality assurance and
chief compliance officer since January 2009. Dr. Giaquinto has over 38 years of experience in the pharmaceutical industry, including 30 years at Schering-Plough Corporation, a publicly held pharmaceutical company that was subsequently acquired
by Merck & Co., Inc., where, from 1972 to 2004, he held executive management positions in the areas of worldwide regulatory affairs and compliance. From 2004 to 2009, Dr. Giaquinto served as the president of ARG Consulting, LLC, a
privately held consulting company. Dr. Giaquinto is a member of the Scientific Advisory Boards of Allozyne, Inc., a privately held biopharmaceutical company, and EndoCeutics, Inc., a privately held biopharmaceutical company. He also served on,
as well as chaired, the Regulatory Affairs Coordinating Committee of the Pharmaceutical Research and Manufacturers of America. Dr. Giaquinto earned a B.S. in pharmacy from St. Johns University and a Ph.D. in pharmaceutics from the
University of Connecticut.

Christopher P. Rusconi, Ph.D. is a co-founder of our company and has served in
several executive positions with us since 2003, most recently as our chief scientific officer. From 2000 to 2003, Dr. Rusconi was director of research for the program in combinatorial therapeutics and assistant research professor of surgery at
Duke University Medical Center. Dr. Rusconi has authored or co-authored more than 20 peer-reviewed publications, including works appearing in Nature, Circulation and the Journal of Clinical Investigation. He is the
co-inventor of our aptamer-control agent technology, the inventor of REG1 and several issued and allowed patents and has led the development of this program since its inception. Dr. Rusconi earned a B.S. in cellular biology from the University
of Kansas, and a Ph.D. in molecular and cellular biology as an National Science Foundation pre-doctoral fellow from the University of Colorado, Boulder. He continued his training as a Jane Coffin Childs postdoctoral fellow at Duke University Medical
Center.

Board of Directors

Dennis Podlesak is our chairman and has served as a member of our board of directors since December 2007. Mr. Podlesak has been a partner of Domain Associates, or Domain, since 2007. Domain
is an exclusively life science focused venture capital firm. From 2007 to December 2009, Mr. Podlesak founded and served as chief executive officer of Calixa Therapeutics, Inc., a privately held biopharmaceutical company, which was acquired by
Cubist Pharmaceuticals, Inc. in December 2009. Additionally, Mr. Podlesak was executive chairman of Corthera, Inc., a privately held biopharmaceutical company, which was acquired by Novartis AG in January 2010. Prior to Domain, from 2005 to
2007, Mr. Podlesak was a founder and chief executive officer of Cerexa, Inc., a privately held biopharmaceutical company, which was acquired by Forest Laboratories, Inc. in 2007. Prior to Cerexa, from 2004 to 2005, Mr. Podlesak served as
the chief executive officer of Peninsula Pharmaceuticals, Inc., which was acquired by Johnson & Johnson in 2005. Prior to Peninsula, Mr. Podlesak served as senior vice president and led a north american business unit for Novartis
AG, a multinational publicly held healthcare company, and as a member of Novartis pharmaceutical executive committee and global leadership team. Earlier in his career, Mr. Podlesak served as vice president and headed the CEC division of
Allergan, Inc., a publicly held multi-specialty healthcare company, and as member of Allergans north american and global management team. Mr. Podlesak spent the first ten years of his career with SmithKline Beecham (now GlaxoSmithKline
plc) where he was promoted to eight positions of increasing responsibility during his tenure with the company. Mr. Podlesak currently serves as chairman of the board of directors of Adynxx, Inc., a privately held pharmaceutical company, and
Syndax Pharmaceuticals, Inc., a privately held pharmaceutical company, and is a member of the board of directors of Avanir Pharmaceuticals, Inc., a publicly held biopharmaceutical company, RightCare Solutions, Inc., a privately held healthcare
technology company, DRI Holdings Limited, and its wholly owned subsidiary, Domain Russian Investments, Limited. Mr. Podlesak received a B.A. in business administration and an M.B.A. from Pepperdine University and has completed postgraduate
studies at the Wharton School, University of Pennsylvania. We believe that Mr. Podlesak possesses specific attributes that qualify him to serve on our board of directors, including his experience as chief executive officer at other companies in
the biotechnology industry, his over 20 years of strategic, operational and commercial experience within the pharmaceutical industry and his service on other boards of directors in the biotechnology industry.

Jesse Treu, Ph.D. has served as a member of our board of directors since July 2005. Dr. Treu has been a partner of
Domain since its inception in 1985. Dr. Treu currently serves on the boards of directors of several of Domains portfolio companies. Recently, Dr. Treu served on the board of directors of SenoRx, Inc., a publicly held biotechnology
company, which was subsequently acquired by C.R. Baird, Inc. Dr. Treu began his career with General Electric Company in 1973. Dr. Treu holds a B.S. from Rensselaer Polytechnic Institute, and both an M.A. and Ph.D. from Princeton
University. We believe that Dr. Treu possesses specific attributes that qualify him to serve on our board of directors including Dr. Treus extensive management and board experience in the healthcare industry.

P. Sherrill Neff has served as a member of our board of directors since July 2005. Mr. Neff founded Quaker Partners
Management, L.P., an investment firm, in 2002 and has served as a partner since 2002. From 1994 to 2002, Mr. Neff was president and chief operating officer of Neose Technologies, Inc., a biopharmaceutical company, and a director from 1994 to
2003. From 1993 to 1994, he was senior vice president of corporate

development at U.S. Healthcare, a publicly traded health maintenance organization which was acquired by Aetna Life & Casualty Co. Prior to that time, Mr. Neff was a managing director at
Alex Brown & Sons, an investment bank, from 1984 to 1993 and a corporate attorney at Morgan, Lewis & Bockius from 1980 to 1984. Mr. Neff holds a B.A. from Wesleyan University and a J.D. from the University of Michigan Law
School. Mr. Neff serves on the boards of directors of Resource Capital Corporation, a publicly held real estate investment trust, and Cempra, Inc., a publicly held clinical stage pharmaceutical company, as well as several privately held
organizations. Mr. Neff also served on the board of directors of Amicus Therapeutics, Inc., a publicly held biopharmaceutical company, from 1996 until 2011. We believe that Mr. Neff possesses specific attributes that qualify him to serve
on our board of directors including his more than 20 years of relevant experience in the healthcare industry and more than eleven years as a founding partner of a leading, healthcare venture capital firm.

Raphaël Wisniewski has served as a member of our board of directors since December 2009. Mr. Wisniewski joined
Edmond de Rothschild Investment Partners, or Rothschild, in 2001 and has served as a partner of its life sciences practice since 2006. He is a former member of the managing board of Rothschild. Mr. Wisniewski is a graduate of the Ecole des
Hautes Etudes Commerciales in Paris and holds a postgraduate diploma in Economics and Finance from the Institut dEtudes Politiques, Paris. We believe that Mr. Wisniewski possesses specific attributes that qualify him to serve on our board
of directors, including his experience investing in and growing biotechnology companies, his experience in finance, capital markets and investing and his understanding of the operations and issues that affect similarly situated private or public
companies.

B. Jefferson Clark has served as a member of our board of directors since and chair of the audit
committee since 2004. Mr. Clark co-founded The Aurora Funds, Inc., or Aurora in 1994 and currently serves as the managing partner of Aurora. He works primarily with Auroras life sciences portfolio. Mr. Clark currently serves on the
boards of several of Auroras private life science portfolio companies. Prior to forming Aurora, Mr. Clark spent 13 years working in development and external affairs for Duke University. Mr. Clark holds a B.S. in Mechanical
Engineering from Duke University and a M.B.A. from the Fuqua School of Business at Duke University. We believe that Mr. Clark possesses specific attributes that qualify him to serve on our board of directors including a significant
understanding of corporate governance issues and the manner in which a board should operate due to his experience serving on the board for over a dozen early stage life science companies and member of the audit committee for several companies.

Anton Gopka has served as a member of our board of directors since December 2012. Mr. Gopka is a managing
director of D-Pharma, the management company of RusnanoMedInvest, LLC, or RMI, a Russia-based pharmaceutical venture capital firms, founded by RUSNANO State Corporation. Mr. Gopka currently serves on the boards of several of RMIs portfolio
companies. In December 2010, Mr. Gopka founded ParaClassics, a privately held classical music internet media portal where he serves as managing partner. Previously, from October 2010 to April 2011, Mr. Gopka was a vice president for
mergers and acquisitions at Barclays Capital, LLC, a subsidiary of Barclays PLC. Prior to Barclays Capital, from October 2008 to October 2010, he was director of mergers and acquisitions at Sistema JSFC. Previously, from April 2006 to October 2008,
Mr. Gopka worked at Dresdner Kleinwort, an investment bank, where he advised on a number of M&A and capital markets transactions. Mr. Gopka received a masters degree from the Moscow State University for International Affairs. He also
earned a corporate finance course diploma from INSEAD. We believe that Mr. Gopka possesses specific attributes that qualify him to serve on our board of directors including his extensive transactional experience in a wide range of industries,
strong healthcare exposure as the managing director of a leading Russian pharmaceutical venture capital firm as well as service on the board of directors for a number of healthcare companies.

Family Relationships

There are no family relationships among any of our
directors or executive officers.

Board Composition

Our board of directors currently consists of seven members, all of whom were elected as directors pursuant to the terms of our third amended and restated investors rights agreement. Our third
amended and restated

investors rights agreement will terminate upon the completion of this offering and there will be no further contractual obligations regarding the election of our directors. Our directors
hold office until their successors have been elected and qualified or until the earlier of their resignation or removal.

Upon
completion of this offering, our board of directors will be divided into three classes: class I, class II and class III, with each class serving staggered three-year terms. Upon the expiration of the term of a class of directors, directors in that
class will be eligible to be elected for a new three-year term at the annual meeting of stockholders in the year in which their term expires.

Our amended and restated certificate of incorporation and amended and restated bylaws that will become effective upon the completion of this offering provide that the authorized number of directors may be
changed only by resolution of the board of directors. Our amended and restated certificate of incorporation and amended and restated bylaws that will become effective upon the completion of this offering also provide that our directors may be
removed only for cause by the affirmative vote of the holders of at least 75% of the votes that all our stockholders would be entitled to cast in an annual election of directors, and that any vacancy on our board of directors, including a vacancy
resulting from an increase in the authorized number of directors, may be filled only by vote of a majority of our directors then in office, even if less than a quorum.

We have no formal policy regarding board diversity. Our priority in selection of board members is identification of members who will further the interests of our stockholders through his or her
established record of professional accomplishment, the ability to contribute positively to the collaborative culture among board members, knowledge of our business and understanding of the competitive landscape.

Director Independence

We have applied to list our common stock on The NASDAQ Global Market. Under the rules of The NASDAQ Stock Market, independent directors
must comprise a majority of a listed companys board of directors within 12 months of the completion of an initial public offering. In addition, the rules of The NASDAQ Stock Market require that, (i) on the date of the completion of the
offering, at least one member of each of a listed companys audit, compensation and nominating and corporate governance committees be independent, (ii) within 90 days of the date of the completion of the offering, a majority of the members
of such committees be independent and (iii) within one year of the date of the completion of the offering, all the members of such committees be independent. Audit committee members must also satisfy the independence criteria set forth in Rule
10A-3 under the Securities Exchange Act of 1934, as amended, or the Exchange Act. Under the rules of The NASDAQ Stock Market, a director will only qualify as an independent director if, in the opinion of that companys board of
directors, that person does not have a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director.

In order to be considered to be independent for purposes of Rule 10A-3, a member of an audit committee of a listed company may not, other than in his or her capacity as a member of the audit committee,
the board of directors, or any other board committee: (1) accept, directly or indirectly, any consulting, advisory or other compensatory fee from the listed company or any of its subsidiaries or (2) be an affiliated person of the listed
company or any of its subsidiaries.

Our board of directors undertook a review of its composition, the composition of its
committees and the independence of each director. Based upon information requested from and provided by each director concerning his background, employment and affiliations, including family relationships, our board of directors has determined that
Messrs. Neff, Clark and Wisniewski, representing three of our seven directors, do not have a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director and that each of these
directors is independent as that term is defined under the rules of The NASDAQ Stock Market.

Our board of
directors also determined that Mr. Clark, one of the three directors who serve on our audit committee, that Mr. Neff, one of the three directors who serve on our compensation committee, and that Mr. Wisniewski, one of the three directors who
serve on our nominating and corporate governance committee, satisfy

the independence standards for those committees established by the applicable rules and regulations of the Securities and Exchange Commission, or the SEC, and The NASDAQ Stock Market. In making
this determination, our board of directors considered the relationships that each non-employee director has with our company and all other facts and circumstances our board of directors deemed relevant in determining their independence, including
the beneficial ownership of our capital stock by each non-employee director. We intend to comply with the other independence requirements for committees within the time periods specified above.

Board Committees

Our
board of directors has established an audit committee, a compensation committee and, upon the completion of this offering, a nominating and corporate governance committee. Each of these committees will operate under a charter that has been approved
by our board of directors.

Audit Committee

Upon completion of this offering, the members of our audit committee will be Mr. Clark, Dr. Treu and Mr. Gopka, and
Mr. Clark will chair the audit committee. Our board of directors has determined that Mr. Clark is independent within the meaning of The NASDAQ Marketplace Rules and Rule 10A-3 under the Exchange Act and qualifies as an audit committee
financial expert within the meaning of SEC regulations and The NASDAQ Marketplace Rules. In making this determination, our board has considered the formal education and nature and scope of his previous experience, coupled with past and present
service on various audit committees. Our board of directors has determined that Dr. Treu and Mr. Gopka are not independent for purposes of these standards because of their relationships with Domain and RMI, respectively. Accordingly, we are relying
on the phase-in provisions of Rule 10A-3 and The NASDAQ Marketplace Rules, as described above under Director Independence. Our audit committee assists our board of directors in its oversight of our accounting and financial
reporting process and the audits of our financial statements.

Upon the completion of this offering, our audit committees
responsibilities will include:

overseeing the independence of our independent registered public accounting firm, including obtaining and reviewing reports from the firm;



setting the compensation of our independent registered public accounting firm;



overseeing the work of our independent registered public accounting firm, including receiving and considering reports made by our independent
registered public accounting firm regarding accounting policies and procedures, financial reporting and disclosure controls;

All audit services to be provided to us and all non-audit services, other than de minimis
non-audit services, to be provided to us by our independent registered public accounting firm must be approved in advance by our audit committee.

Compensation Committee

Upon completion of this offering, the
members of our compensation committee will be Mr. Neff and Mr. Podlesak, and Mr. Neff will be the chair of the compensation committee. Our board of directors has determined that Mr. Neff is independent within the meaning of The
NASDAQ Marketplace Rules. Our compensation committee assists our board of directors in the discharge of its responsibilities relating to the compensation of our executive officers. Upon the completion of the offering, our compensation
committees responsibilities will include:



reviewing and recommending to the board of directors our chief executive officers compensation, and approving the compensation of our other
executive officers reporting directly to our chief executive officer;



overseeing the evaluation of our senior executives;



overseeing, administering, reviewing and making recommendations to the board of directors with respect to our incentive compensation and equity-based
plans;



reviewing and making recommendations to the board of directors with respect to director compensation;



reviewing and discussing with management the compensation discussion and analysis required by SEC rules; and

Upon completion of this offering, the members of our nominating and corporate governance committee will be Dr. Treu, Mr. Clark and Mr. Neff, and Dr. Treu will be the chair of the
nominating and corporate governance committee. Our board of directors has determined that Messrs. Clark and Neff are independent within the meaning of The NASDAQ Marketplace Rules. Upon the completion of the offering, the nominating and corporate
governance committees responsibilities will include:



recommending to the board of directors the persons to be nominated for election as directors or to fill any vacancies on the board of directors, and to
be appointed to each of the boards committees;



developing and recommending to the board of directors corporate governance guidelines; and



overseeing an annual self-evaluation of the board of directors.

Compensation Committee Interlocks and Insider Participation

None of our executive officers serves, or in the past has served, as a member of the board of directors or compensation committee, or
other committee serving an equivalent function, of any entity that has one or more executive officers who serve as members of our board of directors or our compensation committee. None of the members of our compensation committee is, or has ever
been, an officer or employee of our company.

Code of Business Conduct and Ethics

We have adopted a written code of business conduct and ethics that applies to our directors, officers and employees, including our
principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions. Following the completion of this offering, a copy of the code will be posted on the corporate governance
section of our website, which is located at www.regadobio.com. If we make any substantive amendments to, or grant any waivers from, the code of business conduct and ethics for any officer or director, we will disclose the nature of such amendment or
waiver on our website.

The positions of our chairman of the board and chief executive officer are separated. We also intend to appoint a lead independent
director in the event we have a chairman who is not independent within the meaning of The NASDAQ Marketplace Rules. Separating these positions allows our chief executive officer to focus on our day-to-day business, while allowing the chairman of the
board to lead the board of directors in its fundamental role of providing advice to and independent oversight of management. Our board of directors recognizes the time, effort and energy that the chief executive officer must devote to his position
in the current business environment, as well as the commitment required to serve as our chairman, particularly as the board of directors oversight responsibilities continue to grow. Our board of directors also believes that this structure
ensures a greater role for the independent directors in the oversight of our company and active participation of the independent directors in setting agendas and establishing priorities and procedures for the work of our board of directors. Our
board of directors believes its administration of its risk oversight function has not affected its leadership structure.

Although our amended and restated bylaws that will be in effect upon the completion of this offering will not require our chairman and
chief executive officer positions to be separate, our board of directors believes that having separate positions is the appropriate leadership structure for us at this time and demonstrates our commitment to good corporate governance.

Risk is inherent with every business, and how well a business manages risk can ultimately determine its success. We face a number of
risks, including those described under Risk Factors. Our board of directors is actively involved in oversight of risks that could affect us. This oversight is conducted primarily by our full board of directors, which has responsibility
for general oversight of risks.

Following the completion of this offering, our board of directors will satisfy this
responsibility through full reports by each committee chair regarding the committees considerations and actions, as well as through regular reports directly from officers responsible for oversight of particular risks within our company. Our
board of directors believes that full and open communication between management and the board of directors is essential for effective risk management and oversight.

Medical Advisory Board

Our Medical Advisory Board is comprised of many
preeminent scientists and physicians from the cardiovascular field. Our board of directors appoints members to the Medical Advisory Board for a term of one year, renewable at the members option. The current Medical Advisory Board includes:

Paul W. Armstrong, M.D. has served on our Medical Advisory Board since April 2009. He is a senior attending
cardiologist at the University of Alberta Hospital. He is the founding and immediate past president of the Canadian Academy of Health Sciences. Dr. Armstrong received his medical degree at Queens University. After post-graduate training
both there and at the University of Toronto, he undertook clinical and research training in cardiology at the Massachusetts General Hospital, Harvard Medical School and St. Georges Hospital, London, UK. He is the author, or co-author, of
numerous peer-reviewed publications and a member of a number of editorial boards. He is a member of the American College of Cardiology/American Heart Association ST Elevation Myocardial Infarction Guidelines writing committee, CIHRs Institute
of Circulatory and Respiratory Healths Advisory Board and former member of the FDA Cardiovascular and Renal Advisory Committee and the Board of the Council of the Canadian Academies.

Richard C. Becker, M.D. has served on our Medical Advisory Board since April 2009. Dr. Becker serves as the
director of Cardiovascular Thrombosis Research Center at the Duke Clinical Research Institute, or DCRI. Dr. Becker previously spent over a decade at the University of Massachusetts Medical Center, serving in various capacities including
Professor of Medicine, and director of the Cardiovascular Thrombosis Research Center, Coronary Care Unit and Anticoagulation Services. He is a member of numerous professional associations such as the International Atherosclerosis Society, the
International Society on Thrombosis and Hemostasis and the Thrombosis Council of the American Heart Association. Dr. Becker has published numerous articles in peer-

reviewed journals and authored twelve textbooks. He is the founding editor-in-chief of the Journal of Thrombosis and Thrombolysis. Dr. Becker received his MEd in biochemistry and his M.D.
from the University of Cincinnati Graduate School and College of Medicine, respectively, in Ohio. He completed fellowships in Hematology at the Cleveland Clinic and Cardiovascular Medicine at the University of Massachusetts Medical Center. He is an
NIH-funded investigator in the field of platelet biology, and as co-director, Biomarkers Program coordinates several multi-dimensional research projects that employ gene expression profile and proteomic platforms to determine signatures of
thrombosis.

Robert M. Califf, M.D. has served on our Medical Advisory Board since April 2009. Dr. Califf is
currently vice chancellor for Clinical Research, director of the Duke Translational Medicine Institute, and professor of medicine in the Division of Cardiology at the Duke University Medical Center in Durham, North Carolina. He graduated from Duke
University, summa cum laude and Phi Beta Kappa, in 1973 and from Duke University Medical School in 1978, where he was selected for Alpha Omega Alpha. He performed his internship and residency at the University of California at San Francisco and his
fellowship in cardiology at Duke University. He is board-certified in internal medicine (1984) and cardiology (1986) and is a Master of the American College of Cardiology (2006). For 10 years he was the founding Director of the DCRI. He is
the editor-in-chief of Elseviers American Heart Journal. He has been author or co-author of numerous peer-reviewed journal articles and a contributing editor for theheart.org, an online information resource for academic and practicing
cardiologists. Dr. Califf has served on the Cardiorenal Advisory Panel of the U.S. Food and Drug Administration and the Pharmaceutical Roundtable of the Institute of Medicine. He was the founding director of the Coordinating Center for the
Centers for Education & Research on Therapeutics, a public-private partnership among the Agency for Healthcare Research and Quality, academia, the medical products industry, and consumer groups. He is co-chair of the Clinical Trials
Transformation Initiative, a public private partnership with the U.S. Food and Drug Administration, or the FDA, academia, industry and multiple government agencies.

John Eikelboom, M.B.B.S. has served on our Medical Advisory Board since June 2009. Dr. Eikelboom completed training in Internal Medicine and Haematology in Perth, Australia in 1998 and
subsequently undertook a fellowship in Thrombosis Medicine and Clinical Epidemiology at McMaster University. He returned to McMaster in 2005 to take up a Tier II Canada Research Chair in Cardiovascular Medicine. Dr. Eikelboom has published
numerous articles in peer-reviewed journals.

Michael Gibson, M.S., M.D. has served on our Medical Advisory Board
since March 2009. Dr. Gibson received his M.D. from the University of Chicago. He was an intern, resident and chief resident at the Brigham and Womens Hospital, Harvard Medical School. He received his training as an interventional
cardiologist and served as the director of the Coronary Care Unit at Beth Israel Hospital, Harvard Medical School. Dr. Gibson founded PERFUSE, an academic research organization which has served as the angiographic core laboratory and data
coordinating center for a wide variety of studies. Dr. Gibson also edited a textbook entitled Management Strategies in Interventional Cardiology. He has served as lead author of the section on myocardial perfusion imaging in an
imaging textbook which is a companion to Braunwalds Heart Disease. Dr. Gibson is on the editorial board of Circulation and Editor-in-Chief of Clinical Trial Results where he created the first weekly TV show for Cardiologists This
Week in Cardiology.

Neal S. Kleiman, M.D. has served on our Medical Advisory Board since April 2009. After
receiving his medical degree from Columbia University of Physicians and Surgeons in New York, Dr. Kleiman completed an internship and residency in Internal Medicine at Baylor College of Medicine in Houston. He also completed a fellowship in
Cardiology at Baylor College of Medicine. Dr. Kleiman has published numerous manuscripts, book chapters and abstracts. In addition, he is on the editorial board of several journals. Dr. Kleiman is a member of a number of professional
organizations including The American Heart Association Council on Clinical Cardiology and Council on Thrombosis, and he is a fellow of The American College of Cardiology and the Society for Coronary Angiography and Interventions.

A. Michael Lincoff, M.D. has served on our Medical Advisory Board since August 2009. Dr. Lincoff is a Professor of
Medicine at the Cleveland Clinic Lerner College of Medicine of Case Western Reserve University. He holds the Charles and Charlotte Fowler Endowed Chair for Cardiovascular Research at the Cleveland Clinic. Dr. Lincoff has authored or co-authored
numerous peer-reviewed articles. He edited a book entitled Glycoprotein

IIb/IIIa Inhibitors in Cardiovascular Disease. He has also authored numerous book chapters and reviews and presented numerous lectures at various medical meetings and courses. He is the
consulting editor of the American Journal of Cardiovascular Drugs and serves on editorial boards or as a reviewer for a number of peer-reviewed scientific journals. Dr. Lincoff is currently a member of the Cardiovascular and Renal Drugs
Advisory Committee of the United States Food and Drug Administration. Dr. Lincoff is a fellow of the American College of Cardiology and the European Society of Cardiology and a member of the American College of Physicians, scientific councils
of the American Heart Association, and the Sigma Xi Scientific Research Society.

Roxana Mehran, M.D. has served
on our Medical Advisory Board since April 2009. Dr. Mehran is a practicing interventional cardiologist at New York-Presbyterian Hospital, Columbia University Medical Center. She spent several years as an interventional cardiologist before
becoming Director of Clinical Research at the Cardiology Research Foundation at the Washington Hospital Center. Dr. Mehran has written numerous publications on these topics, including a chapter in the book, Principles and Practice of
Interventional Cardiology. Dr. Mehran completed her training in internal medicine at the University of Connecticut. She then continued her studies in cardiovascular medicine and interventional cardiology at the Cardiovascular Institute at Mount
Sinai Medical Center in New York City.

Philippe Menasché, M.D., Ph.D. has served on our Medical Advisory
Board since June 2009. Dr. Menasché obtained his M.D. and Ph.D. degrees from the University of Paris. In addition to his clinical positions, he is currently Director of an INSERM (National Institute of Health and Medical Research)
laboratory devoted to cell therapy of cardiovascular diseases.

Lars Wallentin, M.D., Ph.D. has served on our
Medical Advisory Board since June 2009. Professor Wallentin is chairman of the Committee for National Guidelines for Treatment of Heart Diseases in Sweden, member of the research council of the Swedish Heart Foundation and expert for the Swedish
Government Delegation for the development of Clinical Research. Dr. Wallentin became the first professor of Cardiology at Uppsala University Hospital, Uppsala, Sweden in 1991 and was head of the Department of Cardiology from 1991 to 1999. He founded
the Cardiothoracic Center at Uppsala, becoming its first chairman in 1994 to 1995, and going on to serve as vice chairman from 1995 to 1999. In 2001, Professor Wallentin founded the Uppsala Clinical Research Center, where he has been the director
2002 to 2008. From 1998 to 1999, Professor Wallentin was president of the Swedish Cardiac Society, and from 2000 to 2002, he founded and served as president of the Swedish Heart Association. Dr. Wallentin has published numerous papers, other
publications and book chapters. He is a member of numerous medical societies, task forces, working groups and editorial boards, and is an expert for the Swedish Board of Health and Welfare.

Harvey D. White, DSc has served on our Medical Advisory Board since April 2009. Professor White trained as a cardiologist at
Green Lane Hospital and Harvard Medical School. In recognition of his work on end-systolic volume, infarct artery patency and fibrinolysis, he was awarded a Doctorate of Science by the University of Otago, New Zealand in 1995 and the 1998 Prince
Mahidol Award for Medicine by the King of Thailand. Professor White is an Honorary Clinical Professor, Department of Medicine at the University of Auckland. He is also a fellow of the Royal Australasian College of Physicians, the American College of
Cardiology, the European Society of Cardiology, the American Heart Association, the Cardiac Society of Australia and New Zealand and the Royal Society of New Zealand. He has published numerous peer-reviewed articles, editorials and book chapters. He
is also the associate editor of circulation and editorial board member for several international journals. He has served on the steering committees of several international trial groups.

John H. Alexander, M.D., MHS has served on our Medical Advisory Board since June 2011. Dr. Alexander received his
medical degree from the University of Pennsylvania, School of Medicine. He completed his residency in internal medicine at the Brigham and Womens Hospital, Harvard Medical School. He was a fellow in cardiology at Duke University Medical
Center, where he received training in echocardiography and clinical research training at the DCRI. He joined the Duke faculty in the Division of Cardiology and at the DCRI in 2000, where he is currently an associate professor of Medicine. He is
currently the co-director of cardiovascular research at the Duke Clinical Institute, where he oversees a broad portfolio of cardiovascular clinical trials. He is also the director of site-based clinical research at the Duke Heart Center.

The following table shows the compensation awarded to or earned by our principal executive officer, our two other most highly compensated
executive officers who were serving as executive officers as of December 31, 2012, and all individuals who served as principal executive officer at any time during the fiscal year ended December 31, 2012. The persons listed in the
following table are referred to herein as the named executive officers.

Name and Principal Position

Salary($)

Bonus($)

OptionAwards($)(1)

All
OtherCompensation($)

Total($)

David J. Mazzo

President and Chief Executive Officer

445,765

216,391

74,249

13,594(2)

749,999

Steven L. Zelenkofske

Senior Vice President,

Clinical and Medical

Affairs and Chief Medical

Officer

338,898

115,160

29,709



483,767

Christopher P. Rusconi

Senior Vice President,

Discovery/Preclinical

Development and Chief

Scientific Officer

303,491



67,555



371,046

(1)

Represents the aggregate grant date fair value for grants made in 2012 computed in accordance with FASB ASC Topic 718. The assumptions we used in valuing options are
described in note 2 to our financial statements included in this prospectus.

(2)

Consists of premiums for supplemental life insurance for the benefit of Dr. Mazzo and the related tax gross up benefit.

Annual Base Salary

The compensation of our named executive officers is generally determined by our board of directors, based upon recommendations from the
compensation committee of our board of the directors. The following table sets forth the base salaries for the fiscal year ended December 31, 2012 for our named executive officers.

Name

2012 BaseSalary

David J. Mazzo

$

445,765

Steven L. Zelenkofske

$

338,898

Christopher P. Rusconi

$

303,491

Annual Bonus
Opportunity

In addition to base salaries, our named executive officers are eligible to receive annual cash
bonuses. The annual performance-based bonus each named executive officer is eligible to receive is based on the individuals target bonus, as a percentage of base salary, and an assessment of individual and corporate performance by our
board of directors. Pursuant to their employment agreements, each named executive officer has a target bonus represented as a percentage of base salary, or a target bonus percentage, each of which is set forth below:

Our long-term, equity-based incentive awards are designed to align the interests of our named executive officers and our other employees,
non-employee directors and consultants with the interests of our stockholders. Because vesting is based on continued service, our equity-based incentives also encourage the retention of our named executive officers through the vesting period of the
awards.

We use stock options as the primary incentive for long-term compensation to our named executive officers because they
are able to profit from stock options only if our stock price increases relative to the stock options exercise price. We generally provide initial grants in connection with the commencement of employment of our named executive officers and
annual retention grants at or shortly following the end of each year.

Prior to this offering, we have granted all stock
options pursuant to our 2004 Equity Incentive Plan, or the 2004 Plan, the terms of which are described below under Equity Compensation Plans. All options are granted at no less than the fair market value of our common stock on the
date of grant of each award. All of our stock option grants typically vest over a four-year period. In addition, pursuant to the terms of their respective employment agreements, each of our named executive officers is entitled to 100%
accelerated vesting of options upon a change of control or upon a corporate reorganization. We believe these accelerated vesting provisions will allow our named executive officers to focus on closing a transaction that may be
in the best interest of our stockholders even though the transaction may otherwise result in a termination of their employment and, absent such accelerated vesting, a forfeiture of their unvested equity awards. Additional information regarding
accelerated vesting provisions for our named executive officers is discussed below under Employment Agreements, Severance and Change in Control Agreements.

After a determination by our board of directors that our 2004 Equity Compensation Plan, as amended, or equity plan, contained inadequate
authorized shares for the September 28, 2011 stock option issuances, our board of directors cancelled the options that were originally granted on September 28, 2011 and on April 25, 2012, we regranted such options with the same
exercise price and vesting schedules as the original September 28, 2011 grants, including an aggregate of 43,631 options to Dr. Mazzo, an aggregate of 17,458 options to Dr. Zelenkofske and an aggregate of 39,698 options to
Dr. Rusconi. The vesting terms of the 2012 option grants are described in the footnotes to the Outstanding Equity Awards at Year End table below.

Upon the consummation of this offering, outstanding stock options to acquire 1,406,910 shares of our common stock will be assumed under
our 2013 Equity Compensation Plan, the terms of which are described below under Equity Compensation Plans.

Health and Welfare Benefits

Our named executive officers are eligible to participate in all of our employee benefit plans, including our medical, dental, vision, group life and disability insurance plans, in each case on the same
basis as other employees. Generally, we do not provide perquisites or personal benefits to our named executive officers. We do, however, pay the premiums for supplemental life insurance for the benefit of Dr. Mazzo and the related tax gross up
benefit.

Employment Agreements, Severance and Change in Control Arrangements

Our employment agreement, as amended, with Dr. Mazzo provides for, among other things: (i) an initial annual base salary of
$400,000, (ii) initial eligibility for a target cash bonus of up to 50% of annual base salary, (iii) reimbursement of up to $8,836 per year for supplemental long-term disability insurance and/or supplemental life insurance for
Dr. Mazzos benefit, (iv) 100% accelerated vesting of options upon a change of control or upon a corporate reorganization and (v) in the event of a termination without cause, payments equal to
the sum of 12 months of salary and the target bonus payable bimonthly in accordance with customary payroll practices and continuation of health insurance benefits for 12 months. The agreement further provides that Dr. Mazzo may serve on the
board of directors of up to two other companies so long as such service does not interfere with his duties to us and such other companies are not competitors of ours.

We have entered into an amended and restated employment agreement with Dr. Mazzo which will
become effective upon the consummation of this offering. The amended and restated employment agreement will provide for, among other things: (i) an initial annual base salary of $465,825, (ii) initial eligibility for a target cash bonus of up to 50%
of annual base salary, (iii) reimbursement of up to $8,836 per year for supplemental long-term disability insurance and/or supplemental life insurance for Dr. Mazzos benefit, (iv) in the event we terminate Dr. Mazzos employment
without cause, payments equal to the sum of 12 months of base salary and the target bonus payable bimonthly in accordance with customary payroll practices and continuation of health insurance benefits for 12 months, and (v) in the event
we terminate Dr. Mazzos employment without cause within 12 months following a change in control or Dr. Mazzo resigns for good reason within 12 months following a change in control, (a) payments equal to the sum of
18 months of base salary and an amount equal to 150% of the target bonus payable bimonthly in accordance with customary payroll practices and continuation of health insurance benefits for 18 months and (b) 100% accelerated vesting of his options.
The amended and restated employment agreement will further provide that Dr. Mazzo may serve on the board of directors of up to two other companies so long as such service does not interfere with his duties to us and such other companies are not
competitors of ours.

Our employment agreement, as amended, with Dr. Zelenkofske provides for among other things:
(i) an initial annual base salary of $310,000, (ii) initial eligibility for a target cash bonus of up to 35% of annual base salary, (iii) 100% accelerated vesting of options upon a change of control or upon a
corporate reorganization and (iv) in the event of a termination without cause, payments equal to the sum of 12 months of salary and the target bonus payable bimonthly in accordance with customary payroll practices and
continuation of health insurance benefits for 12 months. The agreement further provides that Dr. Zelenkofske may continue to practice medicine two days per month (or more with our written permission) and may remain on any boards of directors or
advisory boards as long as those positions do not represent a conflict of interest.

We have entered into an amended and
restated employment agreement with Dr. Zelenkofske which will become effective upon the consummation of this offering. The amended and restated employment agreement will provide for, among other things: (i) an initial annual base salary of $375,000,
(ii) initial eligibility for a target cash bonus of up to 35% of annual base salary, (iii) in the event we terminate Dr. Zelenkofskes employment without cause at any time or Dr. Zelenkofske resigns for good reason
within 12 months following a change in control, payments equal to the sum of 12 months of base salary and the target bonus payable bimonthly in accordance with customary payroll practices and continuation of health insurance benefits for 12 months,
and (iv) in the event that, within 12 months following a change in control, we terminate Dr. Zelenkofskes employment without cause or Dr. Zelenkofske resigns for good reason, 100% accelerated vesting of his options. The
agreement will further provide that Dr. Zelenkofske may continue to practice medicine two days per month (or more with our written permission) and may remain on any boards of directors or advisory boards as long as those positions do not represent a
conflict of interest.

Our employment agreement, as amended with Dr. Rusconi provides for among other things: (i) an
initial annual base salary of $265,000, (ii) initial eligibility for a target cash bonus of up to 25% of annual base salary, (iii) 100% accelerated vesting of options upon a change of control or upon a corporate
reorganization and (iv) in the event of a termination without cause or resignation for good reason or a termination for any reason within the period 90 days prior to or 12 months following a change in control,
payments equal to the sum of 12 months of salary and the target bonus payable bimonthly in accordance with customary payroll practices and continuation of health insurance benefits for 12 months.

We have entered into an amended and restated employment agreement with Dr. Rusconi which will become effective upon the consummation of
this offering. The amended and restated employment agreement will provide for, among other things: (i) an initial annual base salary of $309,561, (ii) initial eligibility for a target cash bonus of up to 35% of annual base salary, (iii) in the event
we terminate Dr. Rusconis employment without cause at any time or Dr. Rusconi resigns for good reason within 12 months following a change in control, payments equal to the sum of 12 months of base salary and the
target bonus payable bimonthly in accordance with customary payroll practices and continuation of health insurance benefits for 12 months, and (iv) in the event that, within 12 months following a change in control, we terminate Dr. Rusconis
employment without cause or Dr. Rusconi resigns for good reason, 100% accelerated vesting of his options.

Each of our named executive officers signed a proprietary information, inventions and
noncompetition agreement which provides for, among other things, a one year non-compete following termination of employment.

Outstanding
Equity Awards at Year End

The following table sets forth certain information, on an award-by-award basis, concerning
outstanding equity awards for each named executive officer as of December 31, 2012.